Double Head Research Articles

Synthesis and Surface Activity of N‐coco Propylene Bis‐guanidine Hydrochloride

AbstractMonoguanidine and biguanidine salts are widely studied and used in various fields because of their excellent properties, but the study of bis‐guanidine surfactants of single carbon chain and double head groups connected with spacer groups is relatively lacking. In this paper, N‐coco propylene bis‐guanidine hydrochloride (CPGH) was synthesized by neutralization reaction and guanidine reaction, the structure of the product was characterized through some means. The surface properties of the product were studied by measuring and calculating the surface tension, contact angle, dynamic surface tension and conductivity. Compared with the same type of dodecylguanidine hydrochloride (G−Cl) and dodecyl trimethyl ammonium chloride (DTAC), CPGH has higher efficiency of reducing surface tension. It is also found that the adsorption and diffusion ability of CPGH is proportional to its concentration. The results of electrical conductivity show that the formation of micelles is spontaneous. By studying the microstructure of CPGH with different concentrations, it is found that the morphology of CPGH is related to the surface charge distribution and concentration of micelles.

An energy-efficient unequal clustering routing protocol for wireless sensor networks

Wireless sensor networks have drawn tremendous attentions from all fields because of their wide application. Maximizing network lifetime is one of the main problems in wireless sensor networks. This article proposes an energy-efficient routing protocol which adopts unequal clustering technology to solve the hot spots problem and proposes double cluster head strategy to reduce the energy consumption of head nodes in the clusters. In addition, to balance the energy consumption between cluster heads and cluster members, a hybrid cluster head rotation strategy based on time-driven and energy-driven is proposed, which can make the timing of rotation more reasonable and the energy consumption more efficient. Finally, we compare the proposed protocol with LEACH, DEBUC, and UCNPD by simulation experiments. The simulation results prove that our proposed protocol can effectively improve the performance in terms of network lifetime, energy consumption, energy balance, stability, and throughput.

The Effect of Monosodium L-Glutamate (MSG) Treatment for Short and Long Terms to The Semen Quality of Adult Male Rats

This study was conducted to investigate the effect of MSG treatment for short and long term on the semen quality of adult male rats. Twelve male adult Wistar rats with 200-300g of body weight (BW) and 3-4 month of age were used in this study. The animals were divided randomly into 3 groups. M0 was used as a control, M1 and M2 were given with MSG 4mg/gBW for 15 and 45 days respectively. The experimental animals were sacrificed on the days 16 th (to M1 group) and 46 th (to M0 and M2 groups). The epididymis was isolated and semen quality (motility, viability, concentration, and abnormality of sperm) was evaluated. The results showed motility and concentration of M1 and M2 were not significantly decreased compared to M0. MSG treatment also significantly reduced viability and increased abnormality of sperm. Analysis of sperm abnormality character shows that the use of long-term MSG caused a formation of the primary abnormality (round and double head sperm) and increased the secondary abnormality (bent neck, curve tail, coiled tail, headless, and tailless) compared to control. Conclusion, semen quality decreases with consumed MSG for the long term. For this reason, reconsidering the use of MSG as an enhancer for the teste of food is very important. Keywords: epididymis, Monosodium L-Glutamate, semen quality.

Kinematic error compensation of a double swivel head in five-axis abrasive water jet machine tool

With the improvement of manufacturing technology, five-axis machine tools have solved most of the linear error problems. And the rotating kinematics error problems have come to the front. Rotation tool center point (RTCP) function is one of the most effective solutions. Based on the RTCP function, a double swivel cutting head used in abrasive water jet cutting machine has been selected and its kinematic errors have been investigated through a double ball bar (DBB). And further, a new error mapping method has been built to compensate the geometric error. To verify the effectiveness of the method, a series of experiments have been carried out. The results of the experiments showed that, by applying this method, the precision of the tool cutting path could be improved greatly.

REKONDISI BEBERAPA UKURAN TUBUH TERNAK SAPI PERAH FRIESS HOLLAND DI BALAI PENGEMBANGAN BIBIT DAN PAKAN TERNAK TAMPUSU

COMPENSATORY CONDITION OF SEVERAL MEASURES IN FRIESS HOLLAND DAIRY CATTLE AT TAMPUSU ANIMAL FEED AND SEED DEVELOPMENT CENTER. This study was conducted to assess the compensatory condition of some body sizes of Friess Holland Dairy Cattle at Tampusu Animal Feed and Seed Development Center. Animals used in this study were 23 Friesian Fries Holland (FH) dairy cattle at aged of 7 months to 7 years old using a comparative descriptive research method by comparing the same variables for different samples and using the t-test. Research was done by measuring body weight, chest circumference, shoulder’s height and body length. The maintenance of animals was using a double cage head to head. Feeds given were using forages of 10% / head / day from body weight. Concentrate was fed about 2 kg / head / day. Dairy cows in Tampusu have an average body weight of 401.533 ± 39.47 Kg with a varince coefficient value of 9.8%, an average chest circumference of 174.12 ± 11.15 cm with a varience coefficient value of 6.4%, average shoulder height 136.47 ± 9.16 cm with a variance coefficient value of 6.7%, average body length 139.39 ± 9.56 vm with a variance coefficient of 6.8%. Based on these results, the compensatory condition friess holland dairy cattle at tampusu animal feed and seed development center was increase body weight of 11.6%, chest circumference 6.28% and shoulder height of 6.65%. Keywords: Compensatory condition, body measurements, Friess Holland Dairy Cattle

Ultra-widefield fundus fluorescein angiography in pediatric retinal vascular diseases.

Purpose:To describe the utility of RetCam ultra-wide-field fundus fluorescein angiography in pediatric retinal vascular diseases.Methods:A retrospective chart review was carried out in 43 eyes of 22 pediatric patients who were diagnosed or suspected to have a retinal vascular disease. Fluorescein angiography was carried out using the 130 degree lens of RetCam 3. Fluorescein angiography guided treatment (laser/cryotherapy) was carried out wherever required.Results:Diseases studied included - coats disease, familial exudative vitreoretinopathy, retinopathy of prematurity, congenital retinal folds, double optic nerve head, persistent fetal vasculature and incontinentia pigmenti. RetCam assisted fluorescein angiography was helpful in establishing a diagnosis in 4 patients (18%), in decision making regarding treatment in 18 patients (82%), in deciding need for retreatment in 5 patients (23%), helped in staging of disease in 5 patients (23%) and in detecting clinically subtle findings in 6 patients (27%).Conclusion:RetCam assisted FFA is extremely useful to document peripheral retinal vascular pathologies in pediatric patients and helps to take crucial therapeutic and retreatment decisions.

An Energy-Optimization Clustering Routing Protocol Based on Dynamic Hierarchical Clustering in 3D WSNs

An important issue in the three-dimensional (3D) wireless sensor networks (WSNs) is sensor energy optimization. To alleviate this issue, we introduce a new 3D spherical network structure model, and by combining the original energy consumption model to construct a new method to determine the optimal number of clusters and balance the total energy consumption. Since the different sizes of the clusters are generated by traditional hierarchical clustering, it causes unbalanced energy consumption in the network. To alleviate this problem, we adopt an improved dynamic hierarchical clustering method and implement two strategies that include the following three contributions: the introduction of the distance similarity index to get a better clustering, a double cluster head (CH) strategy to reduce the load of a cluster head in a large cluster, and a node dormancy mechanism to balance the energy consumption of the network. In addition, we also propose the optimal cluster-head function to select the CH of each cluster in each round, and the optimal cluster-head function is constructed based on the residual energy and positions of the nodes. Finally, to optimize the CH election strategy, several parameters of the optimal cluster-head function are determined according to the network structure. The simulation results show that our routing protocol is more robust compared with four other protocols, which is of great significance for the application in 3D environment monitoring.

Visual and Refractive Outcomes Following Simultaneous Phacoemulsification and Pterygium Excision with Conjunctival Autograft

Purpose - This study aims at analyzing the visual and refractive outcomes following simultaneous phacoemulsification and pterygium excision with conjunctival autograft (CAG). Setting-Tertiary eye care hospital in South India. Design-Retrospective study. Methods-508 eyes that underwent simultaneous phacoemulsification with pterygium excision between 2011-2017 were included in the study. Exclusion criteria-Pre-operative astigmatism of > 2 D, grade 3 pterygia, recurrent or double head pterygia, traumatic or complicated cataract. Pre-operative evaluation-clinical examination, keratometry, IOL power calculation, retinoscopy and subjective refraction. Procedure-Phacoemulsification with foldable monofocal IOL followed by pterygium excision with conjunctival autografting using tissue glue. Post-operative follow up-Periodically up to 6 months. Results- Mean pre-operative best corrected visual acuity (LogMAR) was 0.41+/-0.46 with post-operative mean being 0.04+/-0.12 (p=0.001). Mean pre-operative and post operative astigmatism were -1.25+/-0.60 D and -0.73+/-0.58 D (p=0.001) respectively. Mean post-operative myopic spherical error was -0.85+/-0.48 D. 34.33% of the patients had a post-operative refractive error out of which 87.42% had myopia and 12.57% had a hypermetropic error (<1D). 63.27% of the eyes with myopic error had an error of < 1 D. Most commonly seen complication was sub conjunctival haemorrhage followed by graft retraction in 12 and 10 eyes respectively. Conclusion- The combined single step procedure of phacoemulsification with pterygium excision in indicated cases, is safe and effective with good visual outcomes. The post-operative myopic residual error can be anticipated and reduced by slightly under correcting the IOL power in patients with concurrent pterygium to optimize the visual outcome.

Self-Balanced Double Horse Head and Rack-And-Pinion Driven Pumping Unit Based on Intermittent Power Supply Control

Considering the shortcomings of beam pumping unit, a kind of mainstream equipment serving in oilfields of China today, also known as “Kowtow Machine”, such as high energy consumption, low efficiency and disturbance caused to grid, a self-balanced double horse head rack-and-pinion driven pumping unit based on intermittent power supply control is put forward by combining the rack and pinion drive with offset crank slider with intermittent power supply motor control. This unit has the following features: (1) having the quick-return characteristics compared with the existing centric mechanism, i.e. slow move during travel under heavy load, and quick return during travel under light load, which are suitable for pumping unit; (2) utilizing the stable drive through rack and pinion, and employing the double horse head structure to keep the vertical downward force applied by counterweight to beam. Moreover, the counterweight is self-balanced, and receives no additional torque at both ends, so as to improve the force applied to beam; (3) using the microcontroller to control the start and stop of motor, which lowers the loss of motor and its power supply system, so as to reduce the consumption of electric power and enhance the utilization rate of equipment. Additionally, pumping unit is disconnected from grid when it is under no load, in order to reduce the impact on and disturbance caused to grid. We have: (1) completed the structural design of this product, which realizes the energy conservation by around 49.52% compared to the conventional beam pumping unit; (2) finished the prototype of the product after conducting a lot of work including mechanical analysis and design, Solidworks 3D modelling and AutoCAD 2D drafting, Simulink simulation, fabrication, assembly and commissioning; (3) performed the test to verify that the power of the prototype is basically consistent with that in the theoretical analysis, which preliminarily meets the expectation; (4) generalized the prospects on the future application and improvement scheme of this product.

Thermodynamics of self-aggregation of mixed cationic gemini/sodium deoxycholate surfactant systems in aqueous solution

Thermodynamics of interaction between cationic gemini surfactants [C12H25(CH3)2N(CH2)sN(CH3)2C12H25]Br2, (s = 2, 6 or 10, assigned as C12CsC12Br2) and sodium deoxycholate (NaDC) in aqueous solution has been investigated by isothermal titration calorimetry (ITC), fluorescence and turbidity measurements. The critical micelle concentrations for NaDC-rich mixture (cmcmix,12-s-12) were determined by fluorescence method. The cmcmix,12-s-12 values are much smaller than those for pure C12CsC12Br2 surfactants, and decrease as the spacer length ‘s’ increases. There is a strong synergistic effect between two surfactants in the NaDC-rich region. In the higher C12CsC12Br2 concentration range above cmcmix,12-s-12, we did obtain from ITC and turbidity measurements the critical parameters for different events that occur as the C12CsC12Br2 concentration increases, including the critical concentrations (CP, CR, CM) of formation and redissolution for LC of the mixed C12CsC12Br2/NaDC systems and transition to gemini-rich micelles. In comparison with the mixed C12CsC12Br2/NaC systems reported with sodium cholate (NaC), the mixed systems with NaDC have lower cmcmix,12-s-12, CP, CR and CM, and thus different self-aggregation processes are well controlled by surfactant concentration and molar fraction. Importantly, ITC allowed us to directly measure the enthalpy changes corresponding to different self-aggregation processes—redissolution enthalpy (∆HR) of LC of mixed surfactants and transition enthalpy (∆HM) from LC to gemini-rich micelles. Eventually, we discussed the cross-linking effect on NaDC-rich micelles of the gemini surfactant (C12CsC12Br2) with double hydrophobic chains and cationic head groups linked through a methylene spacer.

A Parameter Optimization Simulation Method for Crank Torque of Double Horse Head Pumping Unit Dynamics Model with Cable

Background: Patents revealed that Double Horse Head (DHH) pumping unit is one of the improved models developed from the conventional units, and some unbalanced crank torque may cause high cycle alternating stress which can lead to cracking failure in some key components. This makes the research on simulation of crank torque in beam pumping units a more interesting topic in its maintenance operation. Objective: This paper aims to improve the accuracy of crank torque simulation model for the DHH pumping unit by a parameter optimization method for cable joints. Methods: By using a series of cylinders to model the steel cable, a pumping unit multibody dynamics model was constructed to simulate the crank torque. Then the stiffness and damping coefficient in bushing joint and contact force of cable were treated as the key factors, and a Genetic Algorithms based the method was proposed to optimize them for improving the simulation accuracy of the model. Results: This method was applied to simulate the crank torque of a DHH pumping unit, and the experimental torque was also tested from real unit. Results show that the crank torque simulated from improved model is much closer to the experimental tested torque compared with the original model. Conclusion: The parameter optimization method proposed in this paper greatly improved the accuracy of simulated crank torque in DHH pumping unit multibody dynamics model. Keywords: Double horse head pumping unit, crank torque, genetic algorithms, stiffness and damping coefficient, bushing joint, contact force.

New concept of tunnel boring machine: high performance using water jet and diamond wire as rock cutting technology

Abstract Tunnel boring machines are important tools in underground infrastructure projects. Although being well established equipment, these machinesare based on designsof more than 60 years ago and are characterized by big dimensions, enormous weight and high power consumption. Commercial aspects should be noted too. The model adopted by the TBM industry requires constant replacement of cutter discs and specific labor skills, usually offered by the same manufacturingcompany. In some cases the cost of replacement parts and technical assistance can be higher than the acquisition cost of an entire machine. These aspects are no longer compatible with the concept of sustainability that is an important aspect of currentsociety. While the technical characteristics require a large quantity of steel and several inputs, the adoptedmodel is not competitive. One alternative is looking for new technologies that break the old paradigms and allow the development of high performance concepts with lower social and environmental impact. This studydealswith this opportunity by proposing a high performance tunnel boring machine that makes use of high power water jet and diamond wire to compose a double shield cutter head. It works in two stages. In the fristone, an annular cut is executed by hydrodemolition,and in the second one, the diamond wire station slices the rock core. Only with the action of diamond wire is the rock core separated from the rock mass and the removal process is finished. A smart water jet nozzle movement system is described and non circular tunnels can be executed. The new technologies involved requirea different type of backup system, lighter and smaller. The non-existence of mechanical contact between the equipment and the rock mass at theexcavation front allows low power consumption. The advanced rate and primary excavation cost analyses can also be encountered herein. It shows that it is possible to reach an advanced rate of 174 m/day in soft and porous rock and 0.64 m/day in hard and non porousrock, whereas the NTNU method indicates only 55m/day and 13m/day underrespective conditions. On the other hand, the excavation cost is high for both conditions. One option is to use sand as an abrasive in the water jet process, reducing by half the primary excavation cost. It is reasonable to say that the proposed concept can be considered as an alternative for tunnels in soft rock and high porosity, and needs better performance of the water jet system to become an alternative for hard rock.

Unilateral Double Optic Nerve Head Pits

Unilateral Double Optic Nerve Head Pits

Influence of Structure Support Printing Parameters on Surface Finish of PLA Hemispherical Cups for Emulation of Ceramic Hip Prostheses

Hemispherical hip ceramic prostheses require certain degree of porosity on their external surface so as to fix them by means of osteointegration. This can be achieved with porous mesostructures. In contrast, internal surface needs to be smooth in order to assure appropriate sliding of femoral head. Such specific shapes can be obtained by means of 3D printing. However, in certain printing processes, structure supports are required when overhang exceeds a certain angle. In this case, once supports are removed, joints between supports and prostheses will produce irregularities which will increase roughness on the internal surface of the prostheses. In the future, bimaterial prostheses are to be printed in ceramic with plastic structure supports, which are cheaper than ceramic ones. For doing this, double head printing machines will be used. In the present work, as a first step of research, both prostheses and supports were printed in plastic material. Specifically, PLA, which is a biocompatible polymer, was used. Influence of printing variables for supports on surface finish of internal surface of hemispherical cups after removing supports was studied. Prostheses were obtained by means of Fused Deposition Modelling (FDM) technology. Full factorial design of experiments was performed, with three printing variables: Support Pillar Resolution, Horizontal Offset from Part and part, and Dense Infill Percentage. Regression analysis was carried out. Results showed that Support Pillar Resolution and Horizontal Offset from Part are main parameters factors influencing roughness parameters Ra and Rz. In order to obtain low roughness values, high Support Pillar Resolution should be selected. In case low Support Pillar Resolution was necessary, then high Horizontal Offset from Part would be recommended. In the future, research presented in the present work will help selecting proper values for printing parameters in order to obtain smooth internal surfaces of ceramic hemispherical hip prostheses. This will reduce or even avoid subsequent polishing time of the internal surface of the prostheses.

A parameter optimization method for stress simulation of double horse head pumping unit dynamics model with cable

Some components in Double horse head (DHH) pumping unit may occur cracking failure due to high cycle alternating stress, and this makes the research on dynamic stress simulation for them more interesting topic in its maintenance operation. This paper aims to improve the accuracy of dynamic stress simulation model through a parameter optimization method for the cable joints in DHH pumping unit. A series of cylinders was employed to model the steel cable, and the back horse head was also transformed to flexible body, then a rigid-flexible multibody dynamics model with cable was constructed to simulate the dynamic stress of components in DHH pumping unit. Stiffness and damping coefficient in cable joints have a significant effect on the model performance, and an unreasonable value may cause a strong vibrational and undesirable model response, therefore, a Memetic Algorithms based method was proposed to optimize them for improving the simulation accuracy using tested stress as objective function. Results show that the dynamic stress simulated from improved model is much closer to the experimental test compared with the original model, and these optimized parameters are also valid for the model in other working condition.

Comparative Analysis of Means Detectors in Surabaya - Madiun Cross

One example of technological developments in signaling systems in Indonesia is the use of detection facilities on rail lines. A detector is a device that functions to detect the presence or absence of train facilities on the railroad track. Detection equipment is divided into two types, namely axle counter and track circuit. Track circuit detects the presence of trains on the rails, while the axle counter functions to count train axles. This study aims to find a detection system for facilities that is suitable and in accordance with the conditions of the Surabaya-Madiun cross and find out the characteristics for the installation of detection facilities in accordance with the pathway. To find out the appropriate facility system, the two tools are analyzed in terms of system reliability, environmental influences, advantages and disadvantages, disruptions, maintenance, and operations. The results showed that an effective and efficient way of detecting traffic in Surabaya - Madiun was the detection of a double head axle counter facility. This tool is very suitable to be installed in the emplacement.

Morphological characterization and biocontrol effects of Vibrio vulnificus phages against Vibriosis in the shrimp aquaculture environment

The re-emerging field of phage therapy is the potential biocontrol agents for the transfer of virulence factor and to kill their bacterial hosts. In this study, the lytic Vibrio vulnificus phages were studied to provide a better understanding of phage-host interactions and development of phage therapy. Four new V. vulnificus phages were detected from shrimp aquaculture system, named VV1, VV2, VV3 and VV4. All lytic V. vulnificus phages are the Tectiviruses of the family Tectiviridae with typical double layered elongated icosahedral head and tailless morphology. Lytic V. vulnificus phages which infect other Vibrio isolates were further characterized by long term storage, enzymes treatment, organic solvents treatment, detergents treatment, pH stability, temperature stability, agar bioassay method and one-step growth experiment. The effects of chloroform, acetone, ethyl alcohol, methyl alcohol, ribonuclease (RNase), trypsin, protease, Triton-X100 treatments were not affected the growth of VV1, VV2, VV3 and VV4 phages. These phages (VV1-VV4) were inactivated completely with temperature (over 60 °C), pH (<3 or >12), lysozyme and sodium dodecyl sulfate (SDS) treatment. One-step growth experiments indicated that the latent period was at 3 h and burst size was at 37 °C. Agar bioassay method indicated that the percentage of inhibition was 75% (VV1) and 70% (VV2, VV3 & VV4), respectively. SDS-PAGE analysis of all V. vulnificus phages had similar protein patterns with molecular weight masses of 260, 249, 204, 148, 63, 59, 22 and 15 kDa. Hence, it could be concluded that V. vulnificus phage had a broad lytic spectrum and potential biocontrol of luminous Vibriosis in the shrimp aquaculture system.

Visualization of macrophage recruitment in head and neck carcinoma model using fluorine-19 magnetic resonance imaging.

To evaluate the role of infiltrating macrophages in murine models of single and double mutation head and neck tumors using a novel fluorine-19 (19 F) MRI technology. Tumor cell lines single-hit/SCC4 or double-hit/Cal27, with mutations of TP53 and TP53 & FHIT, respectively, were injected bilaterally into the flanks of (n = 10) female mice. With tumors established, perfluorocarbon nanoemulsion was injected intravenously, which labels in situ predominantly monocytes and macrophages. Longitudinal spin density-weighted 19 F MRI data enabled quantification of the macrophage burden in tumor and surrounding tissue. The average number of 19 F atoms within the tumors was twice as high in the Cal27 group compared with SCC4 (3.9 × 1019 and 2.0 × 101919 F/tumor, respectively; P = 0.0034) two days after contrast injection, signifying increased tumor-associated macrophages in double-hit tumors. The difference was still significant 10 days after injection. Histology stains correlated with in vivo results, exhibiting numerous perfluorocarbon-labeled macrophages in double-hit tumors and to a lesser extent in single-hit tumors. This study helps to establish 19 F MRI as a method for quantifying immune cells in the tumor microenvironment, allowing distinction between double and single-hit head and neck tumors. This technique would be extremely valuable in the clinic for pretreatment planning, prognostics, and post-treatment surveillance. Magn Reson Med 79:1972-1980, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Preparation and Properties of Novel Asymmetric Gemini Alkyl Polyglycosides

AbstractIn order to obtain higher surface activity and lower foaming ability, novel asymmetric Gemini alkyl polyglycosides were synthetized based on tertiary dodecyl dimethyl amine and epoxy chloropropane by adopting chlorination, substitution, and quaternization reactions. The structure of synthesis product was characterized by using Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance spectroscopy and elemental analysis. It was confirmed that the synthesis product was an asymmetric glycoside quaternary ammonium salt with double ionic head groups. The critical micelle concentration of the resulting product was 0.025 g/mL at 20°C and its surface tension was low to 22.8 mN/m. The emulsifying ability and wettability of the product were the same as or even better than those of the commonly used surfactants. Moreover, the product revealed low foaming ability.

Synthesis and aggregation behaviors of a new bis-quaternary ammonium surfactant

Abstract A bis-quaternary ammonium surfactant containing two head groups connected with a propylene spacer coco-tri(hydroxyethyl)-dimethylpropane diammonium chloride (CTHDAC) was synthesized through a two-step reaction process. The two head groups were connected with a propylene spacer, which is distinguished from other surfactants with double head groups, such as gemini and bola form surfactants. Its molecular structure was characterized by Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance ( 1 HNMR). CTHDAC could decrease the surface tension to 39.12 mN/m with the CMC being 4.58 mmol/L. In the contact angle measurement, CTHDAC performed poor compared with dodecyl trimethylamine chloride (DTAC). Further, electrical conductivity, fluorescence property, particle size analysis and TEM micrographs were operated to investigate the aggregation behaviors of CTHDAC in aqueous solution. The results indicate that the large hydrophilic area caused by the strong electrostatic repulsion between head groups makes CTHDAC show a loose arrangement at air/water interface and in the formation of micelles. In addition, the size of aggregates of CTHDAC in aqueous solution is around 200 nm which is irregular spherical.