Dead Spots Research Articles

Abstract PO4-22-12: Robot-assisted nipple-sparing mastectomy using da Vinci SP single-port system: primary results from the pilot trial RASPIM-01

Abstract Background Robot-assisted breast surgery was developed in 2014 for nipple-sparing mastectomy through a concealable lateral chest wall incision smaller. Although successful experiences have been reported using a multi-arm surgical robotic system, collisions between robotic arms and instruments often result in the discontinuation of console workflow and limit the performance of the surgical robot. Compared to multi-armed robot systems, the SP system is single-armed, equipped with flexible instruments containing multiple joints that may avoid instrument collision, a controllable camera reducing visual dead spots, and a designated non-third-party port that allows single-port entry and full deployment of the instrument. The RASPIM-01 trial (NCT05448963) is a single-armed pilot study assessing the feasibility of robot-assisted nipple-sparing mastectomy (NSM) using a new SP system. Method This study is a pilot trial conducted in a single-arm, non-randomized design with a recruitment of 30 participants. The SP surgical robot is used in NSM through the lateral chest wall incisions. The major inclusion criteria are 1) Breast cancer with preoperative clinical tumor sizes less than 5 cm, with an adequate tumor-skin distance of at least 3mm, and without nipple-areolar involvement in at least 1cm around the nipple by image, 2) Breast cancer up to clinical stage IIIA (T3, N1-2) showing adequate response to neoadjuvant therapy and meeting criteria 1), 3) Germline pathogenic/likely pathogenic BRCA1 or 2 variant carriers with or without a breast cancer diagnosis, requiring unilateral or bilateral therapeutic mastectomy or prophylactic mastectomy. Exclusion criteria include extensive breast skin or nipple involvement such as inflammatory breast cancer, Paget’s disease, nipple discharge associated with malignancy, image suggestive of cancer involvement of the nipple and subareolar tissue, and stage III breast cancer without response to neoadjuvant therapy, and previous radiotherapy of the surgical side breast. The endpoint measurements include Primary endpoint: The ability to complete nipple-sparing mastectomy with an SP system in the per-protocol population without additional assistant port or conversion to open surgery. Statistical analysis includes point estimation with a 95% confidence interval to analyze the mean or proportion of key performance parameters. No interim analysis will be performed due to the limited number intended to recruit. Results The study recruited 30 breast cancer patients and conducted 30 NSMs, while no prophylactic mastectomy case was recruited. The median age was 44 years old, BMI was 22.4 (18.9-30.0) kg/m2. Median tumor size was 3.0 (1.0-14.6) cm, and axillary lymph node metastases were present in 7 cases (23.3%). T2 (13 cases, 43.3%) tumors were the majority, followed by Tis (10 cases, 33.3%), T1 (5 cases, 16.7%), and T3 (2 cases, 6.7%). The anatomical stages of invasive cancer were Ia (16.7%), IIa (26.7%), IIb (16.7%), and IIIa (6.7%), among them 9 (30.3%) received neoadjuvant chemotherapy before surgery. All NSMs met the primary endpoint of successful completion using the SP robot system without conversion to open mastectomy or the addition of an assistant port. Median console time was 108.5 (73-285) min and docking time was 2.5 (1-9) min. Specimen weight was 311.6 (107-838) gm, while 2 (6.7%) cases had their nipple excised due to cancer-involved margin reported from the frozen section. Twenty-six (86.6%) cases received autologous free flap reconstruction, among which 25 (83.3%) cases received DIEP, and 1 (3.3%) received PAP reconstruction. Four cases received implant (2 cases, 6.7%) or tissue expander (3 cases, 6.7%). Conclusion This is the first NSM clinical trial operated with SP surgical robot system and met its primary endpoint showing the feasibility to conduct NSM. Secondary and exploratory endpoints data will be reported after the completion of clinical follow-ups. Citation Format: Wen-Ling Kuo, Chia-Huei Chu, Jung-ju Huang. Robot-assisted nipple-sparing mastectomy using da Vinci SP single-port system: primary results from the pilot trial RASPIM-01 [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-22-12.

Rapid Prototyping of Anomalous Reflective Metasurfaces Using Spray-Coated Liquid Metal.

Reconfigurable intelligent surfaces (RISs) have the potential to improve wireless communication links by dynamically redirecting signals to dead spots. Although a reconfigurable surface is best suited for environments in which the reflected signal must be dynamically steered, there are cases where a static, non-reconfigurable anomalous reflective metasurface can suffice. In this work, spray-coated liquid metal is used to rapidly prototype an anomalous reflective metasurface. Using a pressurized air gun and a plastic thin-film mask, a metasurface consisting of a 6 × 4 array of Galinstan liquid-metal elements is sprayed within minutes. The metasurface produces a reflected wave at an angle of 28° from normal in response to a normal incident 3.5-GHz electromagnetic plane wave. The spray-coated liquid-metal metasurface shows comparable results to an anomalous reflective metasurface with copper elements of the same dimensions, demonstrating that this liquid-metal fabrication process is a viable solution for the rapid prototyping of anomalous reflective metasurfaces.

First Reportof Colletotrichum fructicola Causing Anthracnose on Glycine max in China.

Soybean (Glycine max L.) is one of the important oilseed and vegetable crop worldwide and provides the main source of vegetable oil and proteins for human and livestock (Hartman et al. 2011). In October 2021, approximately 35% of soybean pods suffered from anthracnose in the farmer's field in Chongzhou, Sichuan Province, China (103°40'12"E, 30°37'48"N), and the occurrence area accounted for about 3.3 hm2. Symptoms of soybean were characterized by yellow spots at the initial stage, gradually expanded into dark brown spots, and eventually amounts of small black particles were densely arranged in the wheel shape on dead spots. Diseased spots of soybean pods were cut into pieces and sequentially sterilized in 75% alcohol for 30 s, 4% sodium hypochlorite for 30 s, sterile water for 3 times. After that, these pieces were placed on potato dextrose agar (PDA), and incubated at 25±2°C in the dark for 5-7 days. Single spore was separately picked and transferred to a fresh PDA plate to obtain pure culture isolates. Total six pure isolates were collected, and among them the hyphae of representative isolate 8-B were initially white, turned grey gradually on PDA medium, and the colonial reverse were radiating, whorled or a mixture of both. Conidia of 8-B were septate, hyaline, unicellular, cylindrical, obtusely rounded at both ends with 1 or 2 oil balls inside, and 10.5-17.6 µm in length and 7.0 µm-3.6 µm in width (n=100). The conidial appressoria were brown subspherical, 6.9 µm-13.3 µm in length and 5.6 µm-10.1 µm (n=50) in width. Based on morphological and cultural characteristics, the isolate 8-B was tentatively identified as Colletotrichum gloeosporioides species complex（Weir et al. 2012). To test pathogenicity,the mycelial plugs were inoculated on 20 detached soybean pods at full seed (R6) stage, and three areas of each pod were lightly scratched using a needle prior to inoculation. As controls, the PDA plugs were attached to the pinned-treated pods. Three independent replicates were conducted for control and inoculated pods, respectively. All pods were incubated in a greenhouse at 25 ± 2°C with a relative humidity of approximately 90%. After 4-5 days post-inoculation, typical anthracnose lesions were observed on the inoculated pods while the control pods remained healthy only with small wound spots. The pathogen re-isolated from all the inoculated pods were morphologically identical to the inoculation isolate (8-B). For further molecular verification, the six gene fragments including the internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), chitin synthase 1 (CHS-1), actin (ACT), β-tubulin 2 (TUB2) and calmodulin (CAL) were amplified and sequenced (Weir et al. 2012, Damm et al. 2012), and the obtained sequences were deposited in GenBank (Accession numbers ON960278, ON685214, ON964475, ON974476, ON685215 and ON964477, respectively). All six gene sequences of 8-B had a high identity to C. fructicola (the stand isolate ICMP 18581) with the accession numbers ON960278 (100%), ON974476 (96%), ON685214 (99%), ON964475 (99%), ON685215 (100%), and ON964477 100%), respectively. Anthracnose disease caused by C. fructicola has previously been reported to affect a range of plant hosts worldwide (Guarnaccia et al. 2017). However, it is still unknown on C. fructicola causing anthracnose in soybean in China. This study firstly reports C. fructicola as the causal agent of anthracnose on soybean in the country, and provides a theoretical basis for the diagnosis and control of this disease.

Gradients and instability: Macrozoobenthic communities in the Benguela Upwelling System off Namibia

This is the most comprehensive study to date on the distribution of macrofaunal assemblages of the Oxygen Minimum Zone (OMZ) off Namibia, one of the least studied benthic marine macrofaunas in the world. OMZs are mid- and bottom-waters at continental margins characterized by dissolved oxygen concentrations lower than 0.5 ml O2 l−1. We present the distribution of macrofaunal assemblages between 17°S and 25°S latitudes and between 25 m and 1523 m water depth with a total of 534 taxa. We performed both abundance-based and biomass-based hierarchical clustering analysis, which differ slightly in the resulting assemblages. This difference is due to the greater importance of molluscs in the biomass-based clustering, while the abundance-based analysis seems to shift the importance to the short-lived crustaceans. The Namibian benthic macrofauna, in general, shows high total biomasses and high representativeness of molluscs compared to OMZs worldwide. Evidences suggest that temperature, depth, diffusive hydrogen sulphide flux, interseasonal dissolved oxygen average and dissolved oxygen seasonal variability as significant forces structuring benthic macrofauna in the Namibian shelf. Multivariate analysis defined 6 faunal assemblages. The deepest and shallowest assemblages were the most diverse, but biomass is low in the first and the highest in the second. The major assemblages within the OMZ core areas are found at an interseasonal average dissolved oxygen below 0.4 ml l−1, all of which co-occur quite frequently with diffusive hydrogen sulphide fluxes. Dead spots are found at an interseasonal average dissolved oxygen level below 0.05 ml l−1.

Ion exchange membrane electrodialysis for water and wastewater processing: application of ladder-type membrane spacers to impact solution concentration and flow dynamics.

Concentration polarization, which creates a thin boundary layer along the membranes in electrochemical reactors and electrodialysis-related processes, is one of the main issues. Membrane spacers provide swirling motion in the stream and distribute fluid toward the membrane, which effectively breaks the polarization layer and maximizes flux steadily. Membrane spacers and the spacer-bulk attack angle are reviewed systematically in the current study. The study then in-depth reviews a ladder-type configuration composed of longitudinal (0° attack angle) and transverse (90° attack angle) filaments, and its effects on solution flow direction and hydrodynamics. The review discovered that, at the tradeoff of high-pressure losses, a laddered spacer can provide mass transfer and mixing activity along the channel while preserving comparable patterns of concentration near the membrane wall. Pressure losses are driven by a change in the direction of velocity vectors. Dead spots in the spacer design that are created by the large contribution of the spacer manifolds can be reduced using the high-pressure drop. Laddered spacers also permit long, tortuous flow paths, which help to create turbulent flow and prevent concentration polarization. The absence of spacers produces limited mixing and broad polarization effects. A major portion of streamlines changes direction at ladder spacer strands positioned transverse to the main flow by moving in a zigzag manner up and down the filaments of the spacer. Flow at 90° is perpendicular to the transverse wires in [Formula: see text]-coordinate, no change in [Formula: see text]-coordinate.

Abstract OT3-21-01: A pilot study of robot-assisted nipple-sparing mastectomy followed by immediate breast reconstruction using da Vinci SP ® single-port system

Abstract Introduction- Robotic mastectomy is a novel breast surgery approach accessed from a concealable anterior axillary incision showing better cosmetic outcomes with a scarless front view. The oncological safety awaits further follow-up from clinical trials or registered studies to mature. Compared to older da Vinci systems with multiple arms, the new SP system is single-armed, equipped with flexible instruments and a camera that may avoid instrument collision and dead spots in the surgical field. This trial (NCT05448963) is not only the leading SP mastectomy trial in Asia but also the first one that incorporates autologous flap reconstruction. Methods- -Objectives: To determine the performance, technical algorithm, safety data, and patient-reported outcomes in single-port-accessed nipple-sparing mastectomy using da Vinci SP® system. -Study design: This study is a pilot clinical study conducted in a single-arm, non-randomized design with a goal to recruit 30 participants. The da Vinci SP ® surgical robot is applied in the nipple-sparing mastectomy and axillary lymph node dissection (if indicated) of each enrolled patient in Chang Gung Memorial Hospital Linkou Medical Center. The post-mastectomy reconstructive method may use autologous flaps or implants depending on the type of build, technical feasibility, and flap site availability of the patient. The eligibility criteria include: I. Meet at least one of the following indications of NSM for breast cancer: 1. Preoperative clinical tumor sizes less than 5 cm, with an adequate tumor-skin distance of at least 3mm and above, and without nipple-areolar involvement in at least 1cm around the nipple by image 2. Breast cancer up to stage IIIa (T3, N1-2) as the initial clinical stage showing adequate response to neoadjuvant therapy and meeting criteria 1. 3. Germline pathogenic/likely pathogenic BRCA1 or 2 mutation carriers (actionable mutations including pathogenic and likely pathogenic mutations) with a breast cancer diagnosis or requiring unilateral or bilateral prophylactic mastectomy as a risk reduction procedure II. Age equal to or above 20 years III. ECOG (Eastern Cooperative Oncology Group) performance score 0-1 IV. ASA anesthesia risk class 1~2, and with adequate organ functions Endpoint measures: -Primary endpoint: Ability to complete nipple-sparing mastectomy with da Vinci SP system in the per-protocol population. -Secondary endpoints: Safety measured by adverse events through 30-day post-operative follow up -Exploratory endpoints: Surgical time, blood loss, hospital stay, breast specimen weight, cancer resection margin, nipple-preservation rate morbidity and mortality rate within 30 days of operation, and reoperation within 30 days post-surgery -Statistical analysis: Point estimation with a 95% confidence interval will be used to analyze the mean or proportion of key performance parameters. No interim analysis will be performed due to the limited number intended to recruit. -Trial status: Active recruitment Conclusion: The single-port robotic system features single port access with multi-jointed instruments which is particularly designed for narrow surgical spaces such as mastectomy. The feasibility of applying da Vinci SP systems to robotic nipple-sparing mastectomy and robiotic axillary lymph node dissection will be demonstrated in this study. Citation Format: Wen-Ling Kuo, Chia-Huei Chu, Jung-ju Huang. A pilot study of robot-assisted nipple-sparing mastectomy followed by immediate breast reconstruction using da Vinci SP ® single-port system [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT3-21-01.

Design and Manufacture of an Optimised Side-Shifted PPM EMAT Array for Use in Mobile Robotic Localisation.

Guided wave Electro Magnetic Acoustic Transducers (EMATs) offer an elegant method for structural inspection and localisation relative to geometric features, such as welds. This paper presents a Lorentz force EMAT construction framework, where a numerical model has been developed for optimising Printed Circuit Board (PCB) coil parameters as well as a methodology for optimising magnet array parameters to a user's needs. This framework was validated experimentally to show its effectiveness through comparison to an industry built EMAT. The framework was then used to design and manufacture a Side-Shifted Unidirectional Periodic Permanent Magnet (PPM) EMAT for use on a mobile robotic system, which uses guided waves for ranging to build internal maps of a given subject, identifying welded sections, defects and other structural elements. The unidirectional transducer setup was shown to operate in simulation and was then manufactured to compare to the bidirectional transmitter and two-receiver configurations on a localisation system. The unidirectional setup was shown to have clear benefits over the bidirectional setup for mapping an unknown environment using guided waves as there were no dead spots of mapping where signal direction could not be interpreted. Additionally, overall package size was significantly reduced, which in turn allows more measurements to be taken within confined spaces and increases robotic crawler mobility.

Democratic Dead Spots: Local Elections and Human Development in Brazil

ABSTRACT Democracy’s proponents argue that decentralisation improves service delivery, expands local accountability, and engages citizens in public life. However, the combination of democratisation and decentralisation sometimes sustains subnational authoritarianism, resulting in differential redistribution of power that limit citizens’ ability to pursue and secure public goods. In this article we ask: To what extent do authoritarian enclaves affect well-being? Few studies have systematically examined how basic democratic failures affect human development outcomes at subnational levels. We address this gap by investigating the effects of local “democratic dead spots” in Brazil. This approach yields the first large-scale quantitative analysis of the consequences of subnational authoritarianism for human development. Our unique dataset covers Brazil’s 5,570 municipalities from 2006 to 2018 and lets us estimate the effects of local elections on human development over time and across space, while controlling for common explanations for human development (e.g. local governance, wealth, social policy, and partisanship). We find that local democratic dead spots are associated with systemically low levels of human development performance. Following uncompetitive elections, health outcomes are systemically lower over five years: an entire mayoral term and one year beyond in comparison to other, very similar municipalities. Education outcomes are also systemically lower, but the effect does not extend beyond one mayoral term. The cumulative results suggest that uncompetitive elections undermine human development, at the very least in the short to medium term.

Impact of Damping on Oscillation Patterns on the Plain Piano Soundboard

The influence of internal damping on the vibration of a piano soundboard is investigated using a Finite-Difference Time Domain (FDTD) physical model and experimental measurements. The damping constant of the model is varied according to a range similar to those found with measurements on a real grand piano at different production stages. With strong damping, a clear driving-point dependency of the forced string oscillation on the oscillation pattern of the soundboard is found. When decreasing the damping, this driving-point dependency is decreasing, nevertheless, it is still present. High damping, therefore, decreases soundboard vibration when strings drive the soundboard at the soundboard’s eigenfrequencies. However, such large damping increases soundboard vibrations when strings drive the soundboard at frequencies which are not eigenfrequencies. Therefore, strong damping smooths out the frequency response spectrum of an instrument. Extreme damping without any presence of distinct eigenmodes leads to a radiation of the strings sound spectrum without soundboard filtering. Low damping leads to a strong influence of the soundboard on the string’s radiated sound. Therefore, the amount of soundboard characteristics can be designed to alter internal damping process by choice of materials, including wood or varnish, and geometry. Additionally, damping reduces the presence of ’dead spots’, notes which are considerably lower in volume compared to other notes.

First Report of Target Spot Caused by Rhizoctonia solani AG-6 in Tobacco in China.

Tobacco is an annual and solanaceous crop, which is widely produced in China. In July 2020, tobacco target spot was observed on 50% of tobacco plants in a 5-ha commercial field of Bijie (27.32° N, 105.29° E), Guizhou province, China. Typical symptoms firstly appeared on the old leaves as round watery spots. Then the spots became a diameter of 2 to 20 cm, with concentric ring lines and dead spots. Fifteen small pieces (5 × 5 mm) of leaf tissue were cut from the edge of the lesions, surface sterilized and placed on potato dextrose agar (PDA) medium amended with kanamycin (0.1 mg/ml). Isolate J136, one of five isolates with similar morphology, was selected for pathogen identification. The culture of the isolate on PDA was brown and exhibited radial mycelial growth after incubation at 28 oC in darkness for 5 days. Hyphae of the fungus were white at the beginning, turned light brown to brown at the later stages, and finally became thick and separated. Sclerotia were brown and produced on PDA after 25 days of incubation in the dark. These characteristics were similar to the colony characteristics of R. solani. The genomic DNA of Isolate J136 was extracted using the CTAB method. PCR analyses were conducted using the following primers specifically designed for the detection of individual AGs or subgroups of R. solani: AG-1 IA, IB and IC (Kuninaga 2003), AG-2-1, AG-2-2, IIIB, IV and LP (Carling et al. 2002), AG-3 PT (Misawa 2015), AG-4 HG-I and HG-II (Kuninaga 2003), and AGs-5-6 (Arakawa and Inagaki 2014). Among the 12 specific primer pairs, only AG-6-specific primers amplified a fragment of ca. 230 bp product, indicating that the tested strain belonged to R. solani AG-6. The sequence was deposited in GenBank with accession no. MZ379468. Using BLASTN search, the sequence of the gene was aligned with the voucher specimen, R. solani AG-6. A phylogenetic tree was constructed based on these sequences. After wards, Isolate J136 was tested for hyphal anastomosis reaction using the R. solani AG-6 standard strain according to the method described by Ogoshi (1987). The hyphal diameter at the point of anastomosis was reduced, with obvious anastomosis point, and the death of adjacent cells, indicating their anastomosis reactions (Anderson 1982). Thus, based on the morphological and genetic analyses, the fungus was identified as R. solani AG-6. To verify its pathogenicity, six plants (cv. Yunyan87) at the 5-to-6 leaf stage were inoculated with mycelial PDA plugs (5 mm in diameter). Leaves inoculated with PDA-only plugs served as the controls. Treated tobacco plants were maintained at a temperature range of 15 to 25 oC in a greenhouse with 85% relative humidity. After 5 days inoculation, typical symptoms were observed on the inoculated leaves, whereas no symptoms were observed on the control leaves. Koch's postulates were fulfilled by re-isolation of the pathogen from the diseased leaves. R. solani AG-2-2 is the only previously reported group of R. solani, which causes tobacco target spot in the field (Gonzalez et al. 2011). Therefore, to our knowledge, this is the first report of R. solani AG-6 causing target spot of tobacco in the field in China. Since considerable losses caused by the disease have frequently happened in this region, addition of this new group pathogen in the disease pool can be more problematic. Proper disease control strategies are in need to be developed to prevent further losses.

Electrical Resistive Tomography to Analyse the Flow Behaviour in Redox Flow Batteries

Redox flow batteries (RFBs) are re-emerging as a safe, scalable, efficient and versatile means of large-scale energy storage. Growing adoption of renewable energy generation has ushered a new optimism regarding future reduction in fossil fuel dependency; limiting further harm dealt to the climate and wider environment. However, this momentum demands more efficient energy storage solutions to reconcile power demand and the intermittent nature of wind, solar and tidal energy generation [1]. Without proper storage, reliable back-up generation – largely provided by fossil fuels – will continue to be an unavoidable reality [2]. RFBs utilise the electrochemical properties of dissolved metal ions to store and release energy. Independent sizing of electrolyte storage tanks and flexible power delivery contributes to the flexibility of RFBs compared to alternative battery technologies [3].RFB reactions occur at the electrode-electrolyte interface, and thus the mass transport at this interface is a critical factor in determining the overall RFB performance. Most RFBs use porous electrodes, with a popular choice of material being carbon felt (CF) due to its low cost, chemical stability and high conductivity [4], although the hydrophobic nature of some CF can cause poor electrode ‘wettability’- decreasing the contact area between the electrode and the electrolyte. Further, electrolyte depletion and asymmetric flow can lead to the presence of ‘dead spots’ where the interface is inactive. Many studies have been conducted on CF to improve the electrochemical performance, using surface treatments, compression and channel flow to improve active area, wettability, and species transport [5-7]. These each have direct impact on current density, pressure drop, overpotentials, and energy efficiency. While the flow of electrolyte in the RFB porous electrodes can be modelled using computational fluid dynamics (CFD) [8], and experimentally assessed using x-ray tomography [9,10] and some optical visualisation methods [11], there are limited experimental methods which can be used on entire RFB stacks.In this study, we explore the use of electrical resistive tomography (ERT) to probe the flow of electrolyte through RFB electrodes. ERT has the advantage that it can provide a non-intrusive means of investigating the hydrodynamics of the otherwise opaque cell stack. Measurements were performed using an array of electrodes place around the perimeter of an RFB electrode chamber which contained conventional carbon felt electrodes. Sensitivity maps were generated using the COMSOL Multiphysics platform and compared with experimental measurements. The flow distribution was evaluated by using injections of concentrated KCl solutions into the background electrolyte. Overall, ERT demonstrated promise as a technique for characterising real-time flow dynamics in RFB stacks and for future research into porous electrode and flow field modifications.

Türkiye'de Kültür Bitkilerinde Istilacı Tür Nysius cymoides (Spinola, 1837) (Hemiptera: Heteroptera: Lygaeidae)’ın Yeni Konukçuları ve Yayılma Alanları

In this study the outbreak of the false chinch bug Nysius cymoides (Spinola, 1837) (Hemiptera: Heteroptera: Lygaeidae) was discussed in cultivated plants, in Adana, Adıyaman, Ankara, Aksaray, Çorum, Denizli, Diyarbakır, Elazığ, Erzincan, Eskişehir, Hatay, İstanbul, Karaman, Kastamonu, Kayseri, Konya, Manisa, Mardin, Mersin, Şanlıurfa, Şırnak, Tekirdağ, Tokat, Yalova and Yozgat provinces during summer of 2018-2019. The geographic location and climatic conditions of these provinces are very different. Therefore, studied pest can adapt to different climate conditions. In 2019, the massive presence of this pest caused several damage to crops such as lack of plant development, dead spots on the leaves even the death of plants. Pest outbreaks occur in drought and warm periods; they can be related to ground wastes and depend on the previous crop for other species of the same genus. Due to the highest host diversity, it can rapidly spread to new areas. A specific Integrated Pest Management (IPM) program is so suggested for the related pest.

Budidaya Ikan Gurami (Ospheronemus Gouramy) dalam Kolam Bundar pada Kelompok Pemuda Sabilulungan di Sindangkasih Ciamis

This activity aims to improve the knowledge and skills of gourami cultivators in Sindangkasih Village, Sindangkasih District, Ciamis Regency, and to understand the benefits of circular ponds as technology in gourami cultivation to increase the quality and quantity of gourami production. The method of carrying out activities through several stages, namely: Preparation & coordination; Implementation; Monitoring and evaluation. The implementation stage begins by providing counselling regarding the cultivation of gourami in circular ponds, followed by the provision of circular ponds as another option for cultivation so that the cultivators do not experience many losses. As a result of the activity, the cultivators switched to circular ponds. Hence, water quality is more controlled, stocking density, more efficient and effective feeding, there are no dead spots in circular ponds so that fish is always moving. Dirt is not concentrated in one point and, pests can be tackled faster because water is controlled, and pests are quickly controlled, the mortality rate is low. As a result, the maximum yield of gourami fish is within four months. The circular ponds are different from conventional ponds, where water conditions are not optimally controlled so that pests cannot be predicted and are slow in pest management so that the mortality rate is high.

Micro- and Macromixing in Polymerization Reactors

Abstract The paper deals with the influence of the local mixing state on the product properties in a mass styrene-acrylonitrile copolymerization stirred tank reactor in steady state. Experimental investigations at different stirrer speeds have been carried out in a specially constructed bench scale reactor. The idealized models for microfluid and complete segregation were used to calculate the polymer mass fraction, the weight average polymerization degree and the molecular nonuniformity at the outlet of the reactor. The apparatus operated as an “ideally mixed” continuous stirred tank reactor under all chosed conditions as demonstrated by measurements of the residence time distributions. The results are: the segregation model describes the experimentals at low stirrer speeds and the microfluid model is appropriate at high agitator revolutions. Polymer mass fraction, weight average polymerization degree and molecular nonuniformity as functions of average residence time calculated on the basis of both the idealized models indicate intersection points. A high extent of microfluid must not tend to decrease the molecular nonuniformity. The agitator speed can be limited in such a way that it is just sufficiently high to approximate the residence time distribution of an “ideally mixed” continuous stirred tank reactor in order to avoid dead spots and channelling. Segregation is not dangerous for the reactor performance and the product properties.

The Preliminary Study for Increasing the Productivity of Unit Tamban Lowland Irrigation Area based on Fact Findings of Observations

Unit Tamban is a fork system of lowland irrigation areas in Kapuas District. It has three primary canals, and each of them has a settling pond at the end. Most of the 3,506 ha planting area still apply once a year cropping patterns. A quick assessment based on field observations is carried out to determine the existing problems, including water management, water quality, and soil quality. The problem in the water management system is silting in the primary and secondary canals. The settling pond at the primary canal was no longer functioning, and it makes the silting worse because the water flow became uncontrolled. Water quality is measured with pH and TDS, the average pH at canal water was 4,22, and TDS was 71 mg/l. The soil type is mainly acid sulphate with pyritic materials, mostly 70 cm below the surface. Increasing cropping patterns twice a year requires improving the water circulations and increasing the soil pH higher than five. The problem in the secondary canal is expected to solve by changing the flow pattern from two way to 1-way flow is needed to avoid dead spots of water so that the leaching processes can work well.

A Cooperative Approach to Extend Cellular Coverage via D2D Architecture based on OLSR Protocol

The access part of all cellular network’s generation suffers from common concerns related to dead spots (zones that are not covered by the network) and hot spots (zones where the number of users is higher compared to network resources). During the last decade, lots of research proposals have tried to overcome cellular problems through multi-hop D2D architecture, which is a new paradigm allowing the direct communication between devices in cellular network to enhance network performances and improve user QoS. In this paper, we propose a multi-hop D2D architecture based on the OLSR protocol to extend cellular coverage. Cell-OLSR, which is the proposed adaptation of OLSR for our architecture, allows the exchange of cellular parameters between nodes to choose the best proxy device to forward data to the cellular base station (BS).

Construction, validation and testing of a water table for natural ventilation analysis

Natural Ventilation in mixed mode cooling presents an opportunity to reduce the dependence on air-conditioning for cooling and ventilation, especially in residential buildings. Intuitive design approaches for natural ventilation can lead to less than optimal performance, and performance analysis is necessary for more predictable performance. However, analytical tools such as CFD modelling can be too complex and time consuming to be accessible to design professionals for assessing natural ventilation flows of real buildings with elaborate geometry. Conversely, simplified approaches may not represent the complex conditions in the building. The water table apparatus was developed as an affordable and accessible tool to simulate air movement, visualize ventilation flows, and enable quantitative comparative analysis.This paper summarizes the design and construction of the water table apparatus, the method for conducting experiments, validation of its results, and its use for design analysis. A parametric study of design alternatives is conducted for a residential three-bedroom apartment building, and design decisions such as building orientation, window size and internal obstructions are evaluated. The airflow through the building model was simulated with water, video recordings are used to visualize flow, and still images are processed with graphic filters for quantitative analysis. The quantitative results are in the form of percentage area with access to good ventilation, percentage area with dead spots, air changes per hour, and a preliminary assessment of temperature gradients due to mixed air. The water table apparatus is an affordable, accessible tool that provides visual and quantitative results that are useful in the design of wind-driven natural ventilation.

On Interaction of Elastic Waves with “Semitransparent” Defects

The issues of identifying discontinuities that partially transmit ultrasonic waves are examined. Such defects are widespread in various products and welded joints of metals and plastics. Examples of “semitransparent” defects include lacks of fusion, “dead spots”, slag and other foreign inclusions in welded joints, flokens and oxide films in forgings and rolled products, etc. Moreover, even such well-studied defects as cracks can also partially transmit ultrasonic waves. However, to calculate and adjust the parameters of ultrasonic testing, hollow model reflectors (various drills, grooves, etc.), which do not transmit ultrasound, are traditionally used. The present article states that for the purposes of defect sizing, it is necessary to correctly calibrate and configure the flaw-detector–transducer kit taking into account the peculiarities of detecting defects of various types, including ones that are “semitransparent” for ultrasonic waves. To develop models of artificial reflectors imitating defects semitransparent for ultrasound, it is proposed to classify such semitransparent defects into three groups, viz., defects with filling, intermittent structures, and clogged weld. The main features of defects of these types are considered. Possible approaches to calculating the acoustic paths of ultrasonic flaw detectors when identifying defects of the three indicated types are described. It is noted that analytical and numerical methods can be used for calculating defects with filling; numerical methods should be preferred for intermittent structures; and analytical methods are better suited to defects of the clogging type.

Optimization of pulp production from groundnut shells using chemical pulping at low temperatures

Paper production through chemical pulping has been identified as one of the ideal avenues of exploring the uses of groundnut shells as they are rich in cellulose. Ideally, the cellulose can be used to synthesize fibres that can be converted into useful paper products. In this study, chemical pulping was the chosen process for liberating the fibres as it is effective in dissolving lignin embedded within the cellulose. In addition, the fibres produced have superior physical properties compared to mechanical pulping. It is imperative that optimal conditions are identified for the chemical treatment process, in order to ensure that energy and chemical consumption are minimized. All these measures are aimed at reducing production costs and make chemical pulping economically viable, as compared to the mechanical pulping process which is less costly. Response surface methodology (RSM) was used in this study to evaluate the effect of three independent variables (cooking time, temperature, and sulphidity) on pulp yield and kappa number. These parameters are critical in the chemical pulping process and the optimal conditions obtained were 180 min, 100 °C and 23.6 wt.%, respectively. At the optimal cinditions, the pulp yield was 64.39wt% with a kappa number of 19.5. The results showed that all parameters investigated, had a statistically significant effect on the production of pulp. The increased cooking time was efficient in ensuring complete impregnation of the groundnut shells with chemicals for pulping and ensuring that the dissolution of lignin is not selective and does not result in dead spots inherently compromising the quality of the pulp. On the other hand, lower temperatures limited the peeling effect due to hydrolysis of carbohydrates which increased pulp yield due to a higher cellulose retention. Consequently, this contributed towards obtaining pulp that is well cooked, has a low bleach consumption and a higher quality.

A methodology for quantifying flow patterns in a water-table apparatus for naturally ventilated buildings

Wind-driven ventilation in buildings is an effective way of diluting the indoor air for maintaining thermal comfort and acceptable indoor air quality. Visualization of the wind-induced flow patterns in a building using a water-table apparatus is a relatively convenient method that produces instantaneous results. The present study focused on the quantification of the flow patterns generated in and around buildings using water-table experiments. The flow patterns were analyzed photographically to derive different ventilation metrics, such as dead spots, ventilation efficiency, etc., which would reveal quantitative information regarding the flow in the different zones of the building. Experiments were conducted using different configurations in order to verify the results obtained with the photographic method. The method used in the present study could be useful in the prediction of flow patterns for complex geometries, which would assist in undertaking early decisions for the proper orientation of a building and its openings. Abbreviations: ACH: Air Changes per Hour (h−1); AS: Room with windows on adjacent walls configuration; AVE: Absolute Ventilation Efficiency; BHK: Bedroom, Hall, Kitchen; C: dye concentration at a point after t, s (g/l); CFD: Computational Fluid Dynamics; Ci: average inside concentration(g/l); Cmax: maximum dye concentration at a point (g/l); Co: initial concentration at a point (g/l); Cs: concentration in the outdoor supply air (g/l); d: characteristic length (mm or m); D: Dining room; dC: change in concentration (g/l); DS: Dead Spots; Ea: Absolute Ventilation Efficiency; fps: Frames per seconds; IAQ: Indoor Air Quality; k reactivity rate (h−1); K: Kitchen; L: Living Room; MATLAB: Matrix Laboratory; OS: Room with windows on opposite walls configuration; P: Dimensionless penetration factor; P1: Passage 1; P2: Passage 2; P3: Passage 3; Pix: Pixel value (px); PNG Portable network graphics; R1: Room 1; R2: Room 2; R3: Room 3; Re: Reynolds Number; RGB: Red, Green, Blue; S: indoor source emission rate (μg/h); SS: Room with single-sided window configuration; T1: Toilet 1; T2: Toilet 2; T3: Toilet 3; U: Utility room; V: Room volume, m3; v: velocity (m/s); VLC: VideoLAN Client