Expensive Energy Sources Research Articles

Design and simulation of efficient solar thermal water heating system for textile industries in Pakistan

Pakistan is facing a severe crisis of energy since 2004. The core causes behind this crisis of energy are the lack of usage of advanced tools in policy development and planning, poor governance and dependency on other sources of energy which are also limited. In this research the design of a solar thermal system to produce hot water at a specified temperature has been presented as solar energy is available in abundance. A flow rate of 80 tons per day of hot water has been assumed. This system may run for 16 hours a day and it will require 5 tons of water per hour at the input. Water at ambient temperature of 25℃ enters the system and hot water at 75℃ is produced by the system. This design is implemented on TRNSYS software which validates the temperature achievement of 75℃ at outlet. It is shown that the collector area of flat plate solar collectors is 600m2. This temperature configuration is an essential requirement for textile industry and it is achieved efficiently. It is a good replacement for the industry working with expensive energy sources like diesel, gas or furnace oil.

Dietary supplementation of low levels of unprocessed Mucuna pruriens utilis seed meal induces mild antinutritional entero-physio-metabolic perturbations without compromising performance and meat quality in finisher broilers

The rapidly growing world human population accentuates the need for improved production especially of protein-rich food. Broiler meat production offers opportunity to ensure security of this food. However, the production of modern broilers is not only limited by high feed costs due to dietary use of expensive energy and protein sources but also their meat possesses undesirable quality attributes. This study thus examined the effect of dietary Mucuna pruriens utilis seed meal (MSM) on growth performance, blood profile, carcass traits, and meat quality in finisher broiler chickens. In a completely randomised design (CRD), 320 21-day-old chicks were randomly allocated to 32 pens in which they were allotted 4 dietary treatments with 0, 2.5, 5, and 10% MSM, each with 8 replicate pens of 10 birds, for 28 days. Growth performance, carcass characteristics, internal organs, haemato-biochemistry, and meat quality were measured. Results showed that dietary MSM did not affect (P > 0.05) broiler performance, weights, and lengths of carcass cuts and internal organs, haematology, and meat quality. The only exception was MSM-induced increase in duodenal weight (linear, P < 0.05) and serum phosphorus (quadratic, P = 0.05) in contrast to a decrease in procalcitonin (quadratic, P < 0.01) and serum levels of total protein (linear, P < 0.05; and quadratic, P < 0.01), albumin (quadratic, P < 0.05), and bilirubin (quadratic, P = 0.001). Therefore, MSM could be supplemented up to 10% without compromising performance, carcass traits, internal organs, haemato-biochemistry, and meat quality in finisher broiler diets.

Perspectives of photovoltaic energy market development in the european union

Photovoltaic (PV) energy has recently been gaining much attention worldwide. It is the least expensive energy source which can be used to replace part of the energy from fossil fuels. The European Union (EU) published the European Green Deal in 2019 with the aim of achieving climate neutrality. The PV solar energy market has gained technological maturity and can help to achieve these climate targets. This article provides an analysis of PV energy usage in the EU by comparing the consumption of PV energy in EU countries. The study is important because there has been a shift from fossil fuels to renewable energy sources. The PV energy is getting more interest worldwide as a source of clean and cheap energy. The data were then analyzed for the world, the EU, and the USA. The main sources of information were the Statistical Office of the European Communities (EUROSTAT) data and International Renewable Energy Agency (IRENA) data. Extended methods were used to check the processes in PVs and a multi-step procedure was conducted. The first step was to check the stationarity of the process by using the Augmented Dickey-Fuller test (ADF test), which involved testing two hypotheses. The first hypothesis was that the process of PV capacity is stationary, and the second hypothesis was that the time series process is not stationary. In the second step, descriptive statistics were used to analyze the changes in PV consumption in EU countries. In the third step, an Autoregressive Integrated Moving Average (ARIMA) model was created in which one-dimensional autoregression models and a moving average for forecasting were calculated for each EU country. Finally, the procedure was supplemented with additional information for a prognosis. This research demonstrated a huge increase in the development of PVs in EU countries. All countries of the EU increased their PV capacity from 2000 to 20. The largest PV producers are Germany, Italy, and Spain, and the smallest are Latvia, Bulgaria, and Lithuania. The key policy implications are as follows: the European Union (EU) should finance the changes in the energy sector to a greater extent. Moreover, the PV development in the EU will be dependent on the climate and energy policies. The development of PV will depend on the actions of not only the EU but also global markets players such as China and the USA.

Sorghum, millet and cassava as alternative dietary energy sources for sustainable quail production – A review

Diversification and expansion of the poultry industry with fast-growing and highly prolific birds such as the quail (Coturnix coturnix), could contribute significantly in achieving global food and nutrition security. However, sustainable intensification of the quail relies on the cost of dietary ingredients used during feed formulations. The use of non-conventional energy sources such as sorghum, millet, and cassava in lieu of expensive energy sources such as maize, could ensure sustainable quail businesses. Generally, alternative feedstuffs should be cost-effective and possess comparable nutritional qualities as maize. In tropical countries such as South Africa, the use of sorghum, millet, and cassava in quail diets can serve as ideal alternatives because they have relatively comparable energy values as maize. Furthermore, these alternatives are largely available and easily accessible in many farming areas of South Africa. However, the presence of antinutritional factors such as tannins, cyanides and phytic acid, among others, as well as their high fiber levels may limit their utilization in quail nutrition. Nevertheless, attempts have been made to develop improved varieties with low antinutrient compositions, for instance, low-tannin sorghum varieties are increasingly being fed to poultry birds. Furthermore, there is growing evidence that certain processing techniques such as sun-drying, soaking, boiling and fermentation, among others, can lower the concentrations of antinutrients in these alternative feedstuffs, thus increasing their feeding value. To this end, nutritional feeding trials on the positive effects of sorghum, millet and cassava in quail nutrition are inconsistent, mainly due to differences in cultivar type, harvesting site or environmental conditions, sampling, and handling methods amongst other factors. Thus, the present review aimed to discuss the potential of substituting maize with sorghum, millet, and cassava in quail diets.

Adoption of Briquettes of Organic Matter as an Environmentally Friendly Energy Source in Uganda

Demand for inexpensive alternative fuels and briquettes to bridge the gap between cooking, water heating, and heating production processes has been expanding by the day, due to the current fuel crisis and the ever-increasing costs of electricity and wood charcoal in Kampala and its environs. The goal of this study was to determine the different types of biomass briquettes and associated technology that are available in Kampala. Face-to-face interviews and questionnaires were used to collect data on the numerous varieties of biomass briquettes that are commonly used by Kampala families, as well as the raw materials used by briquette producers. Descriptive statistics techniques were employed. According to the statistics, the most often utilized briquettes in Kampala are stick briquettes, honeycomb briquettes, cylindrical, round, and doughnut-shaped briquettes. While the majority of households continue to use expensive and unreliable energy sources such as wood charcoal, gas, and electricity, using briquettes is less expensive and has the potential to reduce deforestation, minimize waste streams, and reduce indoor air pollution, reduce odors, and increase local job creation. Households that use briquettes lamented a lack of available technology, a lack of equipment for making their own, and a shortage of well-trained or skilled people to assist in waste sorting to gather organic matter for briquette production. It was concluded that carbonized round briquettes are preferred because non-carbonized briquettes are extremely scarce and that a number of factors significantly deterred individuals from investing in biomass briquette technology, including government laxity in providing incentives and a failure to create favorable conditions for individuals to invest in biomass briquette energy production and utilization.

A case involving laparoscopic decortication of a large simple renal cyst using conventional monopolar device.

Introduction and importanceSimple renal cysts are common in adults, but most of them are asymptomatic. Usually, percutaneous puncture is an initial treatment, but laparoscopic decortication may be effective for recurrent simple renal cyst. Herein, we report a case in which a large symptomatic simple renal cyst was treated with laparoscopic decortication using conventional monopolar device.Case presentationA 34-year-old female visited our hospital with chief complaints of back pain and abdominal fullness. Computed tomography showed a right simple renal cyst (diameter: 140 mm). We performed percutaneous drainage with sclerotherapy, but the cyst recurred a month later. Thus, we carried out laparoscopic decortication. We opened the cyst wall via a retroperitoneal approach and trimmed it using monopolar scissors. The operation time was 124 min. The patient's postoperative course was uneventful, and no complications were observed. Following surgery, the patient was asymptomatic.Clinical discussionIn our case, we performed operation using a conventional monopolar device without sealing devices. It has been reported that the use of sealing devices can make laparoscopic surgery safer and reduce the operation time, but we herein report that laparoscopic decortication with a conventional monopolar device is an effective and safe treatment option for symptomatic simple renal cysts and that more expensive energy sources are not required.ConclusionWe successfully performed laparoscopic decortication of a large symptomatic simple renal cyst. This operation is minimally invasive and safe.

How will a carbon tax affect household energy source combination?

Households consider the relative price among various energy sources while selecting the ideal energy source for use in their daily lives. Carbon tax influences the energy choices of households through changes in the relative price among various energy sources. As the rate of carbon tax increases, the cost advantage of inexpensive energy source toward expensive energy source will diminish. Therefore, we expect that households will move from inexpensive to expensive energy. We explore the effect of carbon taxes on household energy source combinations by conducting a microdata analysis of Japanese households. Our results show that increased carbon tax leads to an increased percentage of households using gas, and reduced percentage of households selecting full electrification or kerosene.

Assessment of Wind and Solar Hybrid Energy for Agricultural Applications in Sudan.

In addition to zero-carbon generation, the plummeting cost of renewable energy sources (RES) is enabling the increased use of distributed-generation sources. Although the RES appear to be a cheaper source of energy, without the appropriate design of the RES with a true understanding of the nature of the load, they can be an unreliable and expensive source of energy. Limited research has been aimed at designing small-scale hybrid energy systems for irrigation pumping systems, and these studies did not quantify the water requirement, or in turn the energy required to supply the irrigation water. This paper provides a comprehensive feasibility analysis of an off-grid hybrid renewable energy system for the design of a water-pumping system for irrigation applications in Sudan. A systematic and holistic framework combined with a techno-economic optimization analysis for the planning and design of hybrid renewable energy systems for small-scale irrigation water-pumping systems is presented. Different hybridization cases of solar photovoltaic, wind turbine and battery storage at 12 different sites in Sudan are simulated, evaluated, and compared, considering the crop water requirement for different crops, the borehole depth, and the stochasticity of renewable energy resources. Soil, weather, and climatic data from 12 different sites in Sudan were used for the case studies, with the key aim to find the most robust and reliable solution with the lowest system cost. The results of the case studies suggest that the selection of the system is highly dependent on the cost, the volatility of the wind speed, solar radiation, and the size of the system; at present, hybridization is not the primary option at most of sites, with the exception of two. However, with the reduction in price of wind technology, the possibility of hybrid generation will rise.

Energy poverty effects on policy-based PM2.5 emissions mitigation in southern and central Chile

Residential firewood burning is the main source of PM2.5 emissions in southern and central Chile. In Chile, approximately 4000 premature deaths are observed each year due to air pollution. Mitigation policies aim to reduce dwellings' energy demand and foster cleaner but more expensive energy sources. Pre-existing energy poverty conditions are often overlooked in these policies, even though they can negatively affect the adoption of these measures. This article uses southern and central Chile as a case study to assess quantitatively different policy scenarios of PM2.5 emissions between 2017 and 2050, considering energy poverty-related effects. Results show that PM2.5 emissions will grow 16% over time under a business as usual scenario. If thermal improvement and stove/heater replacements are implemented, PM2.5 reductions depend on the scale of the policy: a 5%–6% reduction of total southern and central Chile PM2.5 emissions if only cities with Atmospheric Decontamination Plans are included; a 54%–56% reduction of PM2.5 emissions if these policies include other growing cities. Our study shows that the energy poverty effect potentially reduces the effectiveness of these measures in 25%. Consequently, if no anticipatory measures are taken, Chile's energy transition goals could be hindered and the effectiveness of mitigation policies to improve air quality significantly reduced.

Effects of dietary oxidized oil on growth performance, meat quality and biochemical indices in poultry – a review

Abstract Lipids (fats and oils) are a concentrated source of energy in poultry diets that improves palatability, feed consistency, provides essential fatty acids and increases the absorption of fat-soluble vitamins. Fresh oil is an expensive energy source and its exposure to air, heat, metallic catalyst during storage and processing may lead to its oxidative deterioration. This review highlights the response of modern poultry to dietary oxidized oil on growth performance, nutrients digestibility, gut health, carcass characteristics, meat quality, blood chemistry and tissue oxidative status. Literature shows that in moderately (peroxide value (PV): 20 to 50 meq kg−1) and highly (PV: 50 to 100 meq kg−1 or above) oxidized oils, lipid peroxidation causes rancid odours and flavours that negatively affect feed palatability, reduces intestinal villus height that decreases the surface area available for nutrients absorption. The oxidation products also damage fat soluble vitamins (A, D, E and K) in blood resulting in an oxidative stress. The use of oxidized oil in poultry diets has no significant effect on dressing percentage, pH and meat colour, whereas carcass weight decreases and drip loss of meat increases. Overall, there is a contradictory data regarding the influence of oxidized oil in poultry feed depending on the PV and inclusion levels. The reviewed literature shows that the use of mildly oxidized (PV &lt; 20 meq kg−1) oil in poultry feed with 4 to 5% inclusion level decreases the feed cost and ultimately cost of poultry production without compromising their growth performance. It can, therefore, partially replace fresh oil as an efficient, cost effective and sustainable energy source in poultry diets.

Feed efficiency in the growth of humpback grouper Cromileptes altivelis with prebiotics dietary modulation

Energy for fish to carry on with its biological activities and growth comes from food that they eat. In artificial diets, protein become the most expensive source of energy so it is necessary to keep the proportion of protein down to the optimum levels for good growth and feed conversion. In another study, prebiotics resulted in good growth of fish using a manufactured prebiotic supplement. Ideally, we want food material available all year, inexpensive and not be in competition with food material for human consumption. In this study, food formulation with prebiotics made from local products were prepared for fish food. In this study sago was the source of carbohydrates, mackerel and land snails were the source of protein. The formulation was fed to humpback grouper Cromileptes altivelis to study the effectiveness on its growth. Ninety humpback groupers (size 9-9.5 cm, weight 10 – 11 g) were reared in 3 fiberglass tanks for four weeks. Each tank had 30 fish, first tank as control without sago and the two tanks with sago in dietary prebiotic pellet. Length and weight gain were recorded every week then growth performance of fish were assessed in the form of Specific Growth Rate (SGR), Food Conversion Ratio (FCR), weight gain daily and length-weight relationship. Food proximate test were carried out separately in the Integrated Chemistry Laboratory, Institut Pertanian Bogor. Data analysis showed a significant difference in the growth performance of humpback grouper through the values of SGR, FCR and average growth daily, between treatment A and B (with sago) and treatment C (control, zero sago). The proximate test displayed lower protein in treatment A (57.95%) and B (55.95%) but higher in treatment C (59.37%), in the contrary to carbohydrate for treatment A (27.80%), treatment B (26%) and treatment C (22.98%).

HYDRAULIC BLOW PRESSURE – AN ALTERNATIVE TO WATER PRESSURE IN HYDROELECTRIC POWER STATIONS

The article shows that an increase in the pressure of the water flow in the hydraulic system after a hydraulic shock (water hammer) can be used to rotate the hydroturbine of a power plant in the same way as when the water pressure is increased in dam hydroelectric plants. The possibilities of using accumulators to stabilize the pressure and flow rate of water after a water hammer are shown. The basic laws of the course of complete and incomplete hydroblow are considered. The advantages of hydraulic shock power plants in comparison with dam hydroelectric power stations and with all other power plants of the same capacity are disclosed. Indisputable advantages include, first of all, the absence of the need for energy consumption from external sources, low costs for design, manufacture and operation. The inertia forces of a constant volume of circulating water are used as a source of renewable energy. The small dimensions of hydroshock power plants make it possible to use them directly in the place of electricity consumption, therefore losses during its transportation are excluded. Water hammer power plants do not affect environmental changes, do not pollute water, air and soil. By regulating the operation of the valves, it is possible to significantly increase the power output of the power plant using modern high-speed solenoid valves or electric valves, which are turned on and off according to a given program. The possibility of using the developed hydraulic shock installation to rotate a bucket hydraulic turbine and generate electricity is being investigated. The widespread introduction of high-impact hydroelectric power plants will permanently get rid of the use of expensive energy sources and keep the human environment clean.

Change in estrogenic activity in stored human urine before reuse as fertilizer

PurposeRecycling of nutrients from human excreta may offer an opportunity for smallholder farms to improve crop nutrition and soil fertility. However, when applying human urine as fertilizer, it may load natural and synthetic estrogens into the environment. To avoid pollution by endocrine disruptors, treatment methods before field application must be implemented. The present study thus aims to evaluate the reduction in estrogenic activity in human urine during the storage period before urine is applied to the field.MethodsThis study evaluated the estrogenic activity in diluted urine (DU) exposed to simulated sunlight (280–700 nm) and under dark conditions for 75 days. Estrogenic activity was analyzed using the recombinant yeast estrogen screen assay. Concentrations of total nitrogen (Ntot), ammonium–N (NH4–N) and dissolved organic carbon were measured, as well as electrical conductivity and pH. Correlation of factors to the reduction of the estrogenic activity was also evaluated.ResultsDecay of estrogenicity occurred in both treatments, though it was faster in DU exposed to light (k = 0.07 day−1) as compared to DU under darkness (k = 0.05 day−1). Exposure of DU to a direct light source enhances decay of estrogenicity, however, losses of available N can be significant.ConclusionsWhile reduction of estrogenic activity in DU stored under dark conditions takes longer, it is easy and does not require expensive equipment, energy sources or profound chemical expertise. Therefore, we suggest storage of DU under dark conditions as the best option for small-scale farmers and households in rural areas of developing countries.

Dynamic Load Scheduling for Energy Efficiency in a Job Shop with On-site Wind Mill for Energy Generation

With growing concern over global warming and increasing fuel costs, manufacturing facilities are seeking strategic and operational changes to achieve energy efficiency in production. On-site energy generation provides a greener and less expensive source of energy but its highly stochastic and intermittent nature makes production planning very complex. Demand Side Management (DSM) for real-time operation has emerged as an effective tool for carbon footprint reduction. In DSM, a local controller installed at the manufacturing facility uses an intelligent algorithm to make dynamic decisions for scheduling production line electrical loads. In this paper, we propose a framework for the intelligent algorithm in a job shop manufacturing facility aimed at minimizing the total electricity cost such that the total order delays are controlled. We consider a manufacturing facility with a wind mill as a source of on-site renewable electricity generation. The intelligent algorithm makes sequential decisions based on weighted objective function involving electricity cost and delay virtual queues while using different information e.g. historical decisions, current state and near future energy expectations from the wind mill. Job shop scheduling problems with traditional objective functions are NP Hard and the dimension of energy efficiency makes the problem more complicated. The intelligent algorithm developed in this paper uses Recurrent Neural Network for predicting electricity from the wind mill for the future time slots. Simulation results confirm that the proposed online algorithm framework for job shop scheduling is an effective DSM approach, outperforming the current industry practices and achieves results comparable to benchmark solutions.

Effect of Ethanolic Extract of &amp;lt;i&amp;gt;Icacinia manni&amp;lt;/i&amp;gt; Tuber on the Reproductive Parameters of Male Rats

The shift from the current energy sources in foods and feeds to a more available and affordable sources have been observed in recent times. This is in an attempt to balance food availability and utilization in the increasing population. A search for an appropriate and a less expensive energy source in poultry feeds has driven poultry farmers to research on <i>Icacinia manni</i>. This plant is widely available mostly in the tropical rain forest in Africa as a wild shrub with large underground tubers of high carbohydrate content. This study was carried out on male rats with <i>Icacinia manni</i> tuber, a product that has been observed to supplement other energy sources in foods and feeds. This research work examined the effects of crude ethanolic extract of <i>Icacinia manni</i> tuber on Sex hormonal levels, Seminalysis and Testicular histology of albino Wistar rats. A total of 40 rats divided into four groups (A, B, C and D) of ten rats each were used for this study. The <i>Icaciania manni</i> tuber was extracted using ethanol. The median lethal dose (LD₅₀) of 894.43 mg/kg of the extract was estimated using albino Wistar mice by intra peritoneal (Ip) route using the method of Larke (1983). Group A served as the control and was treated with distilled water at 5ml/kg. Group B, C and D were the experimental (treated) groups gavaged with 1/10, 2/10 and 3/10 of LD₅₀ respectively for 28 days. On the 28^th day, the animals were anaesthetized with chloroform and sacrificed. Blood samples were obtained by cardiac puncture, centrifuged and serum obtained for hormonal assay. Abdominal dissection was extended to recover the testis for histology and epididymis for seminalysis. The result revealed a highly significant (p>0.05) decrease in testosterone and progesterone levels in group D compared with the control. Apart from estradiol level which was not statistically affected, other hormone levels were increased (p>0.05) in group D compared with the control group. The decrease in sperm concentration was also observed in the treated groups when compared with the control group. The sperm morphology showed severe damage on sperm especially at the neck and head region in the treated group compared to control group. Sperm motility was significantly reduced in the treated groups compared to control group. Histologically, damages to most part of the testis were observed in the treated groups compared to control group. This study finally projects that <i>Icacinia manni</i> tuber has deteriorating effect on male reproductive health.

Experimental study on the flame propagation and laminar combustion characteristics of landfill gas

Biogas is the least expensive renewable energy source with an almost neutral balance of CO2 emissions. As a type of biogas, landfill gas could potentially be used in the internal combustion engines, gas turbines, and industrial furnaces. However, the combustion characteristics of landfill gas, which are the foundations of further use of the landfill gas, are not clear. In this paper, the flame propagation characteristics of landfill gas were measured in a constant volume combustion chamber using a schlieren system. The experiments were conducted over the equivalence ratio range of 0.7–1.4, the pressure range of 0.1–0.5 MPa, the temperature range of 290–380 K, and the methane contents of 47%, 55.5% and 59%. The main influencing factors of the combustion stability and laminar combustion velocity of landfill gas in laminar combustion were also investigated. The results showed that the preferential diffusion or buoyancy instability appeared during the flame propagation process, and flame front exhibited irregular cellular structure and protuberances or the flame core moved upward under the condition that the Markstein number was small or the laminar burning velocity was lower than 0.15 m/s. At the same time, the Markstein number and the stability of the flame front decreased with a lower equivalence ratio and methane content or higher initial pressure. However, the effect of the initial temperature on the Markstein number was not obvious. The unstretched flame velocity and the laminar combustion velocity initially increased and then gradually decreased with the increase of the equivalence ratio, and the maximum values were measured under the condition that the equivalence ratio was 1.1. Furthermore, the laminar combustion velocity of landfill gas decreased with a higher initial pressure or lower initial temperature and methane content.

The Possibility of Organo-Mineral Fertilizer Production from Sewage Sludge

A lot of attention has been paid in current literature to sewage sludge due to its increasing amount and problem with its disposal. In the age of expensive energy sources and depletion of natural feedstocks it is necessary to find ways of reusing and recycling waste. Sewage sludge has a high valuable fertilizing potential. It is known as a rich source of nutrients. In addition, it includes a large amount of organic matter, which could facilitate the bioavailability of macro- and micronutrients and improves the soil structure. However, a direct application of sewage sludge to the soil is restricted by heavy metals content. Sewage sludge commonly includes pathogenic microorganisms and toxic compounds. The aim of the study was to determine the state of the art and availability of technology for fertilizers production based on waste, especially on sewage sludge. As sewage sludge from different wastewater treatment plants varies in its chemical composition and physical properties, it is important to find a local solution to the problem of sewage sludge disposal. It has been found that organo-mineral fertilizers (OMFs) derived from sewage sludge and modified by the addition of mineral fertilizers seem to be suitable for application to the soil. Adding acids or alkali agents provide sterilization and binding of the components. Novel OMFs gave a comparable crop yield response as conventional fertilizers. They show a slow release of nutrients, which is the main advantage in relation to mineral fertilizers.

Ensiled Cassava (Manihot esculenta) Peel and Caged Layers’ Manure Mixture as Energy Source in Cockerel Starter Diet

This research was carried out in which dried cassava peel and dried caged layers’ manure mixed in ratio 5:1 (w/w) was ensiled for 14 days and the mixture used to partially replace maize, an expensive energy source in broiler diets in most developing countries at 0%, 25% and 50% dietary inclusion levels. Feed intake, body weight gain, feed conversion ratio and protein efficiency ratio were monitored for the 28 day period of the trial. Proximate composition of cassava peel meal, poultry manure, fermented cassava peel and dried caged layer manure and the experimental diets were carried out. The results showed that ensiled cassava peels meal evaluated improved some performance indices and positively enhanced nutrient digestibility in cockerel chickens. Therefore, ensiled mixture of cassava peel and caged layers’ manure (ECPCLM) in cockerel starter diet at 50% dietary level support good energy, enhanced gain in eviscerated weight and reasonable cost per kilogramme flesh gained at the starter phase. It is suggested that the nutritive value for cockerels using ensiled cassava peels can be improved.

ПОВЫШЕНИЕ ЭФФЕКТИВНОСТИ ОППОЗИТНЫХ ПОРШНЕВЫХ КОМПРЕССОРОВ ПЕРЕВОДОМ НА СОВЕРШЕННЫЕ ДИСКОВЫЕ КЛАПАНЫ НОВОГО ПОКОЛЕНИЯ

Opposed gas piston compressors are widely used in various manufacturing industries. In this regard, great attention is paid to their improvement, because compressed gas is the most expensive source of energy. Less than 25 % of the electricity consumed for a compressed air passes into the potential energy of its pressure. One of the most critical components of the compressor is the automatic valve, which, to a large extent, determines the efficiency and reliability of the compressor. The paper is dedicated to a review of the automatic valve of the next generation, the main advantage of which is the increased flow area in the gap, which would significantly reduce a power loss during suction and discharge of gas.

A Review of Carbohydrate Nutrition and Metabolism in Crustaceans

AbstractCarbohydrates are the primary energy source in all animal diets and are the least expensive energy source in the diets of aquatic animals. However, the utilization of carbohydrates by aquatic animals is relatively low relative that of terrestrial animals. Compared with those in fish, few studies have examined the nutrition or metabolism of crustacean species. This lack of information is a bottleneck for current research of crustacean physiology, especially that which focuses on nutrition. Specifically, there is a deficiency of research that focuses on glucose transporter proteins (except for glucose transporter (GLUT) family protein), regulators involved in carbohydrate metabolism, and the interaction of different hormones. This paper summarizes the dietary carbohydrate requirements of various crustacean species and reviews the progress of research on carbohydrate utilization and metabolism, with an aim to providing clearer insight into carbohydrate metabolism and laying a theoretical foundation for crustacean physiological research.