Small Packing Research Articles

Geothermal Power, and a Battery as Well

One of geothermal energy’s key advantages is that it’s always on. But making money selling power increasingly requires being able to react to shifts in electric prices by adjusting production up and down. The fact this is a concern now is an indication of the ambition of a new generation of companies that have shown it is possible to use horizontal drilling and fracturing to build subsurface heat exchangers to harvest large amounts of geothermal energy. The geologic potential is huge—there are a lot of places with hot rock at a drillable depth. But monetizing that potential will require grabbing a sizeable share of the market in big states such as California and Texas where the price of electricity can sink toward zero when sunny conditions allow maximum solar power production, and then rebound as the sun sets. This is a pressing concern for Houston-based Fervo Energy because it is one of the first firms in a small pack of innovators to reach the point where it is building a large scale power plant using this emerging technology. Unlike wind and solar, it can deliver power on demand, similar to coal, gas, and nuclear-powered plants that supply baseload power to the electric market. Fervo’s founders play up its ability to deliver power on demand, but they resist the label baseload power provider because, as Jack Norbeck, chief technology officer and cofounder of Fervo, said, “In the future, baseload power will be a thing of the past.” Baseload power plants are not yet an endangered species. There are still large, mostly old fossil-fueled plants providing baseload power that are still around because they were paid for long ago. However, their numbers are declining as they wear out and are hit with demands for costly emission reductions. The initial sales by Fervo’s Cape Station project in Utah will provide baseload power to southern California power suppliers, complying with a unique California rule that requires them to source low-carbon power supplies that are available 24/7. But for new geothermal companies to sell enough power to become significant players in US power markets, they will need to provide what the electricity business describes as “more flexible, dispatchable power.” Big baseload plants ruled the power universe back when regulators set rates high enough to maintain a sizable surplus of generating capacity—ensuring the lights stayed on. Now, in markets such as Texas and California, power pricing rises and falls based on supply and demand, with selling at all times sometimes resulting in very low payments during peak production periods for solar and wind. This is particularly true during seasons where days tend to be sunny and windy with moderate temperatures. “If you are consuming electricity, particularly in the spring and fall, it is an extremely clean grid you are pulling from,” said Christian Gradl, vice president of operations for Fervo during a panel at this year’s Offshore Technology Conference.

Single-phase static immersion-cooled battery thermal management system with finned heat pipes

Effective thermal management is of critical importance to the performance and safety of lithium-ion batteries. However, research on small and medium-sized battery packs remains scarce. This paper proposes a new immersion cooling method. It combines finned heat pipes with a single-phase static immersion fluid, achieving optimal battery pack homogeneity in existing studies while outperforming the performance of conventional immersion cooling. The method is particularly suitable for energy storage batteries and small and medium-sized battery pack cooling applications. This paper presents a verification of the cooling performance of the cooling method through a combination of simulation analysis and experimental validation. The results demonstrate that the cooling method can enable small and medium-sized battery packs to meet the heat dissipation requirements of 3C or even higher discharge rate under natural convection conditions. In the active cooling scenario, when the battery pack is discharged at a 3C multiplier, the cooling scheme of 9 finned heat pipes can reduce the maximum temperature of the flow-submerged cooled battery pack by 6.4 °C and the maximum temperature difference between cells by 5.3 °C. Even when the battery is discharged at an extreme multiplication rate of 6C, the maximum temperature of the battery pack can be maintained at approximately 60 °C, with a maximum temperature difference between cells of around 15 °C. Based on the aforementioned simulation and experimental results, this paper also validates and analyses the main factors affecting the cooling effect of the method, namely the type of submerged liquid and the number of finned heat pipes.

Sandwich-structured bimodal fiber/bead-on-string fiber composite membrane for comfortable PM0.3 filter

Particulate matter (PM) pollution causes critical harm to human health and global environment. However, the protective respirators attain high-performance filtration of the most permeable PM0.3 by tight stacking of fibers and seriously compromising their wearing comfort. Herein, a fluffy sandwich-structured membrane (SSM) composed of bimodal fibrous layers and bead-on-string fibrous layer is designed to endow the air filter with both high-performance filtration and superior thermal-wet comfort. Based on the electrospinning technique, the bimodal fibers made of nano-/submicron-fibers (about 46 nm and 155 nm) are formed by inducing the jet splitting while the bead-on-string fibers consisting of submicron-fibers (≈ 120 nm) and micro-beads (≈ 3.37 μm) are prepared through manipulating the Rayleigh instability of jets. Due to the structural design of small pores and low packing density, the SSM exhibits excellent PM0.3 removal of 99.8%, low filtration resistance of 65 Pa, and high quality factor of 0.097 Pa-1. It also shows long-term filtration stability and durability under high humidity conditions. Moreover, the SSM simultaneously possesses superior thermal-wet comfort of heat dissipation, air permeability of 164 mm·s-1, and water vapor transmission of 7.6 kg·m-2·d-1. This work may offer a novel insight for exploiting high-performance and comfortable personal protective materials.

Clothing and Equipment Fit Among Male and Female Canadian Armed Forces Members.

The fit of military clothing and equipment is essential for the health and safety of military operators. Given the aim of increasing the proportion of women and the known biological and morphological differences between male and female soldiers, an understanding of fit across different items of kit is needed. The aim of this study was to quantify subjective fit ratings of 8 items of military clothing and equipment, including combat shirt, combat pants, rucksack, small pack, tactical vest, fragmentation vest, helmet, and ballistic eyewear as a function of relative stature and occupational group among male and female Canadian Armed Forces members. An online survey was distributed to male and female Canadian Armed Forces members, where fit was reported by participants according to a 7-point Likert acceptability scale. Participants were binned into 1 of 6 (3 males, 3 females) standing stature categories based on percentiles in a male and female distribution that included (1) under 35th percentile stature, (2) 35th to 80th percentile stature, and (3) over 80th percentile stature. Additionally, participants were separated according to occupational group: Group A: Infantry, Combat Engineer, Artillery, Armored; group B: Signals, Medical Technician, Intelligence, Signals Intelligence/Cyber Ops; group C: Supply Technician, Weapons Technician, Vehicle Technician, Electronic-Optronic Technician, Ammunition Technician; other: Not in other groups, examples include: Financial Services Administrator, Cook. This study was approved by the Defence Research and Development Canada Human Research Ethics Committee under protocol 2019-048, Amendment 2. There were significant effects attributable to stature category and occupational group on the fit of equipment. Specifically, fit acceptability of the rucksack helmet, small pack, and tactical vest was significantly affected by occupational group. Differences between stature categories were detected in all items with the exception of the small pack. Military equipment fit has previously been shown to have implications for protection, performance, and mobility. The results of the investigation demonstrate different patterns of fit acceptability in male and female soldiers across items of clothing and equipment and may require different solutions.

Simulations-based investigation of the effectiveness of fire suppression techniques for safe, large-scale storage of Li-ion batteries

Thermal runaway and subsequent fire in Li-ion cells and battery packs is of much concern in the safety of practical electrochemical energy storage systems. While much of the past work in this direction has focused on single cells or small packs, there is a relative lack of understanding of thermal runaway related fire and fire suppression strategies for large-scale systems, for example in storage and transportation of Li-ion cells. This work presents a simulations-based investigation of strategies for effective prevention and suppression of thermal runaway propagation and resulting fire in pallets containing a large number of Li-ion cells. The impact of location, orientation and flowrate in sprinklers supplying a liquid coolant is quantitatively investigated. It is shown that a minimum flowrate is needed for effective fire containment, beyond which, additional flowrate does not offer much incremental benefit. The orientation of sprinklers with respect to the trigger pallet undergoing thermal runaway is found to strongly impact the effectiveness of fire suppression. Fire suppression in the case of vertically stacked pallets is also investigated. Interesting synergistic effects involving a combination of liquid coolant along with one or more suppressant gases is demonstrated. The key output of this work is a computational model that quantitatively predicts the effectiveness of fire suppression techniques for battery transportation and storage. Results presented here offer a fundamental understanding of an important practical problem in battery-based energy storage. Results may form the basis of design and optimization to ensure the safety of large-scale storage and transportation of Li-ion cells.

Giant seebeck effect in an undoped single crystal of 2,5,8-triphenylbenzo[1,2-b:3,4-b':5,6-b'']trifuran

Abstract The application of 2,5,8-triphenylbenzo[1,2-b:3,4-bʹ:5,6-bʹʹ]trifuran (Ph3-BTF) as a thermoelectric generator is demonstrated. An undoped single crystal of Ph3-BTF exhibited a giant Seebeck effect (GSE) with a large negative Seebeck coefficient of up to −239 mV K−1 at a base temperature of 350 K. Ph3-BTF features a small reorganization energy and tight molecular packing in the single crystal (π–π stacking distance: 3.32 Å), which may contribute to the observed GSE.

Role of RIPK1 kinase in neuronal-glial network adaptation under hypoxic conditions

Cerebral hypoxia is a condition characterized by a reduced oxygen supply to tissues that plays a crucial role in the pathogenesis of numerous neurodegenerative diseases. In hypoxia, intracellular signaling cascades are activated, ultimately leading to various forms of nerve cell death. The initiation of necroptosis under hypoxic conditions is governed by PIPK1 kinase, and its inhibition could potentially offer neuroprotection against hypoxic damage [1–3]. Studies investigating the effects of blocking RIPK1 kinase on the activity of neuronal-glial networks are currently lacking. Consequently, RIPK1 kinase constitutes a promising objective for further exploration. Thus, the aim of this work is to examine the part played by RIPK1 kinase in the adjustment of neuronal-glial networks amid hypoxia. The study focused on primary cultures of nerve cells in the hippocampus of mouse embryos belonging to the C57Bl/6 line. Hypoxia was induced in vitro on the 14th day of culturing the nerve cells. The RIPK1 kinase inhibitor was administered 20 minutes prior to, during, and after the hypoxia intervention. After 7 days of the stress induction, the calcium and bioelectrical activity of the neuron-glial networks were evaluated. Calcium activity was assessed via the Oregon Green 488 BAPTA-1, AM (Thermo Fisher Scientific, USA) using a Zeiss LSM 800 confocal laser scanning microscope (Carl Zeiss, Germany). The experiments assessed total percentage of oscillating cells in culture, the frequency, and duration of calcium events. The analysis of bioelectrical activity was conducted using the MEA 60 multi-electrode arrays from Multichannel Systems. The registered signal from the arrays was processed through the MEAMAN algorithms in MATLAB (Certificate of State Registration of Computer Program No. 2012611190). The average number of small network packages and spikes was estimated. Under physiological conditions, spontaneous calcium activity is observed by the 21st day of neuron-glial network development. The percentage of cells exhibiting calcium events is 60.64 ± 3.68%, the frequency of calcium oscillations is 1.52±0.22 osc/min, and the duration is 9.63±0.75 s. During hypoxia modeling, the percentage of cells exhibiting calcium events decreased to 34.77±4.08%, and the frequency of calcium oscillations decreased to 0.64±0.08 osc/min. The inhibition of RIPK1 kinase maintains the percentage of cells exhibiting calcium events at the level of intact cultures, which is 60.38±3.4%. By the 21st day of culturing primary nerve cell cultures under physiological conditions, spontaneous bioelectrical activity forms. This is indicated by parameters such as the average number of small network clusters and spikes. Hypoxia modeling has a negative impact on the development of spontaneous bioelectrical activity. In the “Intact” group, the average number of small network packs was 36.12±4.27 packs per 10 minutes, while in the cell culture with hypoxia, it was 15.87±3.03 packs per 10 minutes. Additionally, the “Intact” group had an average of 90.22±12.32 spikes, while the cell culture with hypoxia had only 11.58±4.7 spikes. However, blocking RIPK1 kinase during hypoxia preserved the average number of small network packs (23,49±2,14 packs/10 min). Thus, inhibiting RIPK1 kinase under hypoxic conditions preserves the proportion of cells that exhibit spontaneous calcium events and partially preserves spontaneous bioelectrical activity.

A bioinspired vine-like hierarchically structured PET/CA composite nanofibrous membrane with superhydrophobic and superoleophilic surface for high-efficiency cooking fumes capture

Indoor air pollution, especially from cooking oil fumes (COFs), has become a serious issue that affects human health. Obtaining filters that can offer high efficiency, high air permeability and good reusability and stability for COFs removal remains a challenge. Herein, a bioinspired vine-like polyethylene terephthalate/cellulose acetate (PET/CA) composite nanofibrous membrane with high filtration performance, high air permeability and enhanced flame retardancy for COFs removal is achieved via a one-step co-electrospinning process. The nanofibrous membrane consists of hierarchically branched nanofibers to offer small pore size (0.48 μm), high porosity (94.75 %) and low packing density (0.22 g m−3), as well as surface superhydrophobicity (water contact angle of 154°) and superoleophilicity (vegetable oil wetting time of 0.21 s). The nanofibrous filter demonstrates high-efficiency COFs removal (>99.5 %), low air resistance (<70 Pa) and good reusability and stability for actual COFs purification. By virtue of the simple fabrication technique and the superiorities in COFs capture, the bioinspired vine-like hierarchical structured nanofibrous membranes have promising applications for oily fumes filtration and air purification in the catering industry.

Reviewing the Legal Framework Applicable to Cross-border E-commerce Transactions in Brazil

E-commerce transactions increased substantially over the past three years, including the cross-border movement of goods that were acquired using the internet. From the customs legislation point of view, such new reality means a huge volume of import transactions of goods using the post or courier companies, having individuals as importers, and which values are quite low if compared to ordinary importations made by companies. The flood of small packs not only clogged the old logistic system involved in this kind of transaction but also evidenced the failure of the current legal framework. On top of this issue, local producers argue that products acquired from the generically called ‘Asian e-commerce marketplaces’ are artificially cheaper, and they claim for controls, restrictions, and more equal conditions in terms of tax treatment. The debate pointed out above is global by nature, and it is a hot topic in Brazil. The goal of this paper is to present the political debate regarding e-commerce cross-border transactions, and the recent developments in terms of the legal framework, challenges, and opportunities.Isabelle Ruiz Guero* Brazil, International Trade, customs, cross-border transactions, postal and courier imports, e-commerce, tax reform

Tobacco purchasing in Australia during regular tax increases: findings from the International Tobacco Control Policy Evaluation Project

ObjectiveWe examined Australian tobacco purchasing trends, the average self-reported price paid within each purchase type and the association between type of tobacco product purchased and participant characteristics, including quit intentions,...

Pilot Testing of a Lightweight, Pulmonary Assist System in an Ambulatory Sheep Model of Destination Therapy Respiratory Support.

A new, lightweight (2.3 kg), ambulatory pulmonary assist system (PAS) underwent preliminary evaluation in ambulatory sheep. The PAS was purposefully designed for long-term extracorporeal respiratory support for chronic lung disease and utilizes a novel, small (0.9 m 2 surface area) gas exchanger, the pulmonary assist device, with a modified Heart Assist 5 pump fitting in a small wearable pack. Prototype PAS were attached to two sheep in venovenous configuration for 7 and 14 days, evaluating ability to remain thrombus free; maintain gas exchange and blood flow resistance; avoid biocompatibility-related complications while allowing safe ambulation. The PAS achieved 1.56 L/min of flow at 10.8 kRPM with a 24 Fr cannula in sheep one and 2.0 L/min at 10.5 kRPM with a 28 Fr cannula in sheep 2 without significant change. Both sheep walked freely, demonstrating the first application of truly ambulatory ECMO in sheep. While in vitro testing evaluated PAS oxygen transfer rates of 104.6 ml/min at 2 L/min blood flow, oxygen transfer rates averaged 60.6 ml/min and 70.6 ml/min in studies 1 and 2, due to average hemoglobin concentrations lower than humans (8.9 and 10.5 g/dl, respectively). The presented cases support uncomplicated ambulation using the PAS.

Studies of proline conformational dynamics in IDPs by 13C-detected cross-correlated NMR relaxation

Intrinsically disordered proteins (IDPs) are significantly enriched in proline residues, which can populate specific local secondary structural elements called PPII helices, characterized by small packing densities. Proline is often thought to promote disorder, but it can participate in specific π·CH interactions with aromatic side chains resulting in reduced conformational flexibilities of the polypeptide. Differential local motional dynamics are relevant for the stabilization of preformed structural elements and can serve as nucleation sites for the establishment of long-range interactions. NMR experiments to probe the dynamics of proline ring systems would thus be highly desirable. Here we present a pulse scheme based on 13C detection to quantify dipole–dipole cross-correlated relaxation (CCR) rates at methylene CH2 groups in proline residues. Applying 13C-CON detection strategy provides exquisite spectral resolution allowing applications also to high molecular weight IDPs even in conditions approaching the physiological ones. The pulse scheme is illustrated with an application to the 220 amino acids long protein Osteopontin, an extracellular cytokine involved in inflammation and cancer progression, and a construct in which three proline-aromatic sequence patches have been mutated.

Investigation of propagation of thermal runaway during large-scale storage and transportation of Li-ion batteries

Thermal runaway in Li-ion cells and battery packs impacts the safety and performance of electrochemical energy storage systems. In particular, preventing the propagation of thermal runaway in large-scale battery storage and transportation of batteries is of much importance. While most of the past work in this direction addresses single cells or a small battery pack, only limited literature is available on systems of larger size. This work presents multiphysics simulations of propagation of thermal runaway during large-scale storage and transportation of Li-ion cells. Through simulations that account for multimode heat transfer, Arrhenius heat generation, turbulent fluid flow and combustion, the propagation of thermal runaway from one pallet of cells to an adjacent pallet is studied. The model quantitatively predicts the temperature field in/around the pallets, and, in particular, predicts whether the adjacent pallet will also catch fire or not. The impact of state of charge of the cells on thermal runaway propagation is examined. Results indicate that the gap between pallets plays a key role in determining propagation. A sharp threshold value of the gap is found, beyond which, propagation does not occur. Results from this work may be helpful in ensuring thermal safety during large-scale storage and transportation of Li-ion cells, ultimately contributing towards improved electrochemical energy storage and conversion.

Modelling Aero-Structural Deformation of Flexible Membrane Kites

Airborne wind energy systems using flexible membrane wings have the advantages of a low weight, small packing volume, high mobility and rapid deployability. This paper investigates the aero-structural deformation of a leading edge inflatable kite for airborne wind energy harvesting. In the first step, a triangular two-plate representation of the wing is introduced, leading to an analytical description of the wing geometry depending on the symmetric actuation state. In the second step, this geometric constraint-based model is refined to a multi-segment wing representation using a particle system approach. Each wing segment consists of four point masses kept at a constant distance along the tubular frame by linear spring-damper elements. An empirical correlation is used to model the billowing of the wing’s trailing edge. The linear spring-damper elements also the model line segments of the bridle line system, with each connecting two point masses. Three line segments can also be connected by a pulley model. The aerodynamic force acting on each wing segment is determined individually using the lift equation with a constant lift coefficient. The particle system model can predict the symmetric deformation of the wing in response to a symmetric actuation of the bridle lines used for depowering the kite (i.e., changing the pitch angle). The model also reproduces the typical twist deformation of the wing in response to an asymmetric line actuation used for steering the kite. The simulated wing geometries are compared with photogrammetric information taken by the onboard video camera of the kite control unit, focusing on the wing during flight. The results demonstrate that a particle system model can accurately predict the geometry of a soft wing at a low computational cost, making it an ideal structural building block for the next generation of soft wing kite models.

Optimizing Sterilization Packaging through Root Cause Analysis: An Exploration into Sealing Defects of Paper-Plastic Pouches.

BACKGROUND Paper-plastic sterilization pouches are essential in healthcare for preventing instrument contamination. However, sealing defects in these pouches can jeopardize patient safety. To address this issue, our study uses Root Cause Analysis (RCA), aiming to identify contributing factors to these defects and propose practical solutions. Through this, we aim to enhance the overall sterilization process. MATERIAL AND METHODS A retrospective analysis was conducted on 35,762 instruments sterilized and packaged in paper-plastic pouches at our hospital's Central Sterile Supply Department (CSSD) across two periods: July 2020 to June 2021 (pre-RCA, 17,563 instruments) and September 2021 to August 2022 (post-RCA, 18,199 instruments). We evaluated RCA scores, packaging personnel's perceptions of sealing quality, and sealing defect rates before and after RCA implementation. RESULTS Root causes for sealing defects included lack of a standardized inspection procedure, inadequately sized packing table, missed inspections, incorrect distribution procedures, inadequate staff training, and insufficient lighting through the pass-through window between storage and distribution rooms. Among these, lack of a standardized inspection procedure, small packing table size, and missed inspections were statistically significant risk factors (P<0.05). The sealing defect rate decreased from 0.15% pre-RCA implementation to 0.07% post-RCA implementation. CONCLUSIONS Implementing RCA has been shown to effectively enhance the CSSD staff's perception of sealing quality and significantly reduce the incidence of sealing defects in paper-plastic pouches. Thus, RCA serves as an invaluable tool for quality improvement in sterilization packaging processes.

Olfactory stimulus as environmental enrichment for shelter dogs: a pilot study

Environmental enrichment techniques include olfactory stimuli for improving animal welfare. This study aimed to analyze the reactions of 41 shelter dogs exposed to odorous stimuli, such as the method used in another study on wild canids. The focal animal method analyzed the dogs’ reactions, with all behaviors recorded. Behavioral responses were classified as positive (P+), negative (N-), or other (Ot). Independent variables were all dogs and the size of the packs. The behavior between the basal (without stimulus), exposure, and after-stimulus withdrawal was analyzed. For all dogs, olfactory stimuli significantly increased P+ (P=0.001) and N- (P=0.004), contrasting with the decrement of Ot behaviors (P=0.001) from the basal to the exposure phase. After the withdrawal of the stimuli, P+, N-, and Ot behaviors returned to basal levels (P&gt;0.05). There were no significant differences (P&gt;0.05) in the conduct of small or large packs exposed to stimuli. Dogs are sensitive to olfactory stimuli, but arousal is generalized to P+ and N-. It is undesirable to an N- increase for improvement of animal welfare. Contrary to what was observed in a study with wild canids, the method failed in shelter dogs because N- was increased. The introduction of sudden novelty (olfactory stimulus) in an impoverished shelter environment may have caused excitement in the dogs. It is suggested that changes in the method, such as stimuli exposition to each dog in an isolated room, are necessary to increase sheltered dog well-being.

Interfacial assembling of flexible silica membranes with high chlorine resistance for dye separation

Inorganic membranes have gained extensive attention due to their more uniform pore size, higher flux, and better chemical stability over traditional polymeric membranes. However, the development of inorganic membranes still faces substantial obstacles in the form of a difficult preparation procedure and the high cost of a large-scale synthesis. Herein, a facile interfacial assembly strategy is designed to prepare flexible silica membranes by the close and strong packing of ultra-small nanoparticles via crosslinking with trimesoyl chloride. Profiting from the extremely small size and tight packing of silica nanoparticles, the permeance of flexible silica membrane with a uniform pore size of 3.4 nm exceeds 210 L m−2 h−1 MPa−1, which is nearly 11 times higher than the polyamide membrane simultaneously ensuring the rejection effect. Meanwhile, the flexible silica membrane has no performance deterioration after exposure to 50000 ppm h of chlorine (NaOCl), indicating its excellent chlorine resistance. The facile interfacial assembly strategy applied for the synthesis of the membrane is highly reproducible and scalable (high-performance silica membrane with 100 cm2 has been obtained), which has overall flexibility after the curvature of 100 m−1, paving the way for the development of future applications.

Taro (Colacasia esculenta (L.) SCHOTT) value chain in Veracruz, Mexico

Objective: To identify and analyze the links of the taro (Colocasia esculenta) value chain in Actopan, Veracruz, Mexico, focusing on its deficiencies and opportunity areas, and to simulate the yields generated by this crop. Design/Methodology/Approach: The research was carried out in the town of Santa Rosa, in Actopan, Veracruz, Mexico, with local producers and manufacturers, using both an exploratory and a random descriptive method and a qualitative and quantitative approach. Direct observation, interviews with key informants, and reflection and analysis workshops were carried out to find out which are the links of the value chain and how they operate within the taro agroecosystem in the study region. Results: The links between inputs supply, production, harvest and post-harvest, collection and distribution, transformation-packing-crating, and commercialization were determined. The main limitation was the area cultivated by half of the producers (0.5 to 3.0 hectares) who obtain an average annual yield of 50 t ha-1. The cost of agricultural inputs is high, the market prices for the product are low, and pest organisms impact the production. Regional middlemen (both retailers and wholesalers) are in charge of commercialization and most of the agreements are informal. The main market for taro and its destination is international (90% for the American market). The best organized packing plant has a 126 to 169% monthly yield. Study Limitations/Implications: Performance simulations must be carried out in medium and small packing plants to obtain an overall comparison. Findings/Conclusions: The production and commercialization of taro in the study area generate economic income and local employment throughout the year. Taro also has lower production costs than other crops, as well as a high return on investment. Overall, it benefits the economic agents of the value chain. However, the lack of organization of the participants does not allow them to use economies of scale or to access preferential markets. Consequently, the economic benefits are not distributed equally among all the links.

Comparative evaluation of the effectiveness of intracanal and intraoral cryotherapy on postendodontic pain in patients with symptomatic apical periodontitis: A randomized clinical trial.

There is a rising need for controlling postendodontic pain (PEP) without using analgesics and other conventional methods. The aim of the study is to compare the effectiveness of various cryotherapy applications on controlling PEP in patients with symptomatic apical periodontitis. One hundred and eight patients were selected and preoperative pain and pain on percussion scores were recorded using Numeric Rating Scale (NRS) and Visual Analog Scale (VAS), respectively. After obtaining consent, the access cavity was prepared under local anesthesia. After cleaning and shaping, the patients were randomized into the following groups: Group A: Canals were given final irrigation with 20 mL room temperature saline solution for 5 min, Group B: Canals were given final irrigation with 20 mL cold (2°C-4°C) saline solution for 5 min, and Group C: After obturation and restoration procedures, small ice packs of size 2 cm × 2 cm × 2.5 cm (wrapped in sterile gauze) were placed intraorally on the vestibular surface of the treated tooth. At 6 h, postoperative pain was measured using NRS and at 24 h, pain and pain on percussion were measured using NRS and VAS, respectively. Data were analyzed using SPSS software. There was a significant reduction in postoperative pain in the intracanal and intraoral groups at 6 and 24 h when compared with the control group individually. There was no significant difference in postendodontic between intracanal and intraoral cryotherapy groups at 6 and 24 h. Both intracanal and intraoral cryotherapy applications are effective in reducing PEP in patients with symptomatic apical periodontitis.

Prospective Submodule Topologies for MMC-BESS and Its Control Analysis with HBSM

Battery energy storage systems and multilevel converters are the most essential constituents of modern medium voltage networks. In this regard, the modular multilevel converter offers numerous advantages over other multilevel converters. The key feature of modular multilevel converter is its capability to integrate small battery packs in a split manner, given the opportunity to submodules to operate at considerably low voltages. In this paper, we focus on study of potential SMs for modular multilevel converter based battery energy storage system while, keeping in view the inconsistency of secondary batteries. Although, selecting a submodule for modular multilevel converter based battery energy storage system, the state of charge control complexity is a key concern, which increases as the voltage levels increase. This study suggests that the half-bridge, clamped single, and full-bridge submodules are the most suitable submodules for modular multilevel converter based battery energy storage system since, they provide simplest state of charge control due to integration of one battery pack along with other advantages among all 24 submodule topologies. Depending on submodules analysis, the modular multilevel converter based battery energy storage system based on half-bridge submodules is investigated by splitting it into AC and DC equivalent circuits to acquire the AC and DC side power controls along with an state of charge control. Subsequently, to validate different control modes, a downscaled laboratory prototype has been developed.