Utilization Of Alternative Energy Sources Research Articles

The interplay between glucose and ketone bodies in neural stem cell metabolism.

Glucose is the primary energy source for neural stem cells (NSCs), supporting their proliferation, differentiation, and quiescence. However, the high demand for glucose during brain development often exceeds its supply, leading to the utilization of alternative energy sources including ketone bodies. Ketone bodies, including β-hydroxybutyrate, are short-chain fatty acids produced through hepatic ketogenesis and play a crucial role in providing energy and the biosynthetic components for NSCs when required. The interplay between glucose and ketone metabolism influences NSC behavior and fate decisions, and disruptions in these metabolic pathways have been linked to neurodevelopmental, neuropsychiatric, and neurodegenerative disorders. Additionally, ketone bodies exert neuroprotective effects on NSCs and modulate cellular responses to oxidative stress, energy maintenance, deacetylation, and inflammation. As such, understanding the interdependence of glucose and ketone metabolism in NSCs is crucial to understanding their roles in NSC function and their implications for neurological conditions. This article reviews the mechanisms of glucose and ketone utilization in NSCs, their impact on NSC function, and the therapeutic potential of targeting these metabolic pathways in neurological disorders.

Green marketing's effect on customer satisfaction and awareness: an empirical study

Environmental sustainability has emerged as a major concern in today's corporate world. Governments are concerned about environmental issues. The term "green" has gained popularity in today's world. Green marketing refers to the strategy of endorsing goods or services that are friendly to the environment, and contribute positively to the earth. It boosts a company's brand and preserves the ecosystem. A boost of companies to use eco-friendly procedures and the provision of more sustainable choices to customers are the two main objectives of green practices marketing. The study goes through to evaluates consumers' awareness of green marketing, ascertains the pros and cons and obstacles of implementing green marketing, and analyses the elements that induce a consumer to choose green sustainable goods, the study is carried down with the locality respondents present around Chikkmagaluru district through the Forms and it concludes that Green marketing is a tool for preserving natural resources and safeguarding the environment for future generations, utilization of alternative energy sources to produce goods and services are ways to achieve sustainable growth. Green marketing had a positive impact on the worldwide market equally.

Forecasting wind power using Optimized Recurrent Neural Network strategy with time‐series data

AbstractFuel prices are rising, bringing attention to the utilization of alternative energy sources (RES). Even though load forecasting is more accurate at making predictions than wind power forecasting is. To address the operational challenges with the supply of electricity, wind energy forecasts remain essential. A certain kind of technology has recently been applied to forecast wind energy. On wind farms, a variety of wind power forecasting methods have been developed and used. The main idea underlying recurrent networks is parameter sharing across the multiple layers and neurons, which results in cycles in the network's graph sequence. Recurrent networks are designed to process sequential input. A novel hybrid optimization‐based RNN model for wind power forecasting is proposed in this research. Using the SpCro algorithm, a proposed optimization method, the RNN's weights are adjusted. The Crow Search Optimization (CSA) algorithm and the Sparrow search algorithm are combined to form the SpCro Algorithm (SSA). The suggested Algorithm was developed using the crow's memory traits and the sparrow's detecting traits. The proposed system is simulated in MATLAB, and the usefulness of the suggested approach is verified by comparison with other widely used approaches, such as CNN and DNN, in terms of error metrics. Accordingly, the MAE of the proposed method is 45%, 10.02%, 10.04%, 33.58%, 94.81%, and 10.01% higher than RNN, SOA+RNN, CSO+RNN, SSA+DELM, CFU‐COA, and GWO+RNN method.

Electrochemical hydrogen storage in carbon nitride electrode using modified reversible polymer electrolyte membrane fuel cell

The human population is now through a process of evolution, whereby there is a gradual shift towards the adoption and utilization of alternative energy sources and technologies for energy storage. In this transition process non-availability of renewable energy sources round the clock is one of the key hurdles. It is possible to meet continuous energy demands by storing excess renewable energy as hydrogen. The presented experimental investigation focuses on a modified reversible fuel cell (MRFC) with a solid carbon-based substance (carbon nitride) integrated into it as a host for electrochemical hydrogen storage. The method for electrode fabrication from carbon nitride powder and PTFE binder and a lab-scaled MRFC is disclosed. The developed MRFC with an integrated hydrogen storage electrode is put through electrochemical testing, and the results are presented. Galvanostatic charging and discharging is done, and the results are examined to ascertain the electrode's electrochemical hydrogen storage capacity. The electrochemical hydrogen storage capacity of the porous carbon nitride electrode is found to be 1.15 wt%, which is comparable to intermetallic metal hydride-based hydrogen storage mediums viz. AB2 and AB5. The obtained results showed the feasibility of a MRFC with an integrated carbon nitride-based hydrogen storage electrode, making it the first device of its kind. Besides, porous carbon nitride is proved to be a potential candidate for reversible electrochemical hydrogen adsorption. This will contribute to the clean energy sector and surely a step forward toward hydrogen economy.

Effects of compression ratio on thermodynamic and sustainability parameters of a diesel engine fueled with methanol/diesel fuel blends containing 1-pentanol as a co-solvent

Researchers are intensively seeking to meet the ever-increasing energy demand worldwide. In this context, it is known that many studies have been carried out. The utilization of alternative energy sources is important both in meeting the energy demand and in reducing environmental pollution. In this direction, it is recommended to use clean fuels that can be employed in internal combustion engines. One of these fuels is methanol. However, it is known that phase separation occurs when methanol is blended with diesel fuel due to its poor mixing capability, but it is possible to avoid this phase separation by using different techniques in practice. One of them is to use co-solvent. Pentanol (C5H12O) stands out as a fuel additive that helps to blend diesel-methanol blends in a stable structure due to its phase stability-enhancing properties. In other words, diesel/methanol/pentanol blends can form a stable, transparent, and homogeneous fuel mixture. In the literature, there are a limited number of studies using the above fuel combination. In addition, these studies have classically evaluated engine characteristic results and emission parameters without detailed thermodynamic analysis. Investigating the use of these fuels in engines in terms of thermodynamics and sustainability at different engine operating parameters can provide important information on whether these fuels can be used as an alternative. The present study deals with the thermodynamic and sustainability analyses of a single-cylinder DI diesel engine when it was operated at several compression ratios (CRs) (16:1 and 18:1) and engine loads (25 %, 50 %, 75 %, and 100 %) to analyze the engine characteristics and pollutants. In this study, 1-pentanol as a co-solvent is infused into methanol/diesel blends with the intention of avoiding phase separation. In this context, M5P5 (90 % diesel fuel, 5 % methanol, and 5 % 1-pentanol) and M10P10 (80 % diesel fuel, 10 % methanol, and 10 % 1-pentanol) fuel combinations were prepared. The results were compared with conventional diesel fuel aiming to present the novelty of the fuel blends. To conclude, the experimental results pointed out that the CI engine consumed more alternative fuel blends because of their lower calorific value as compared to diesel fuel to provide the same output power for each tested fuel sample. It can be exhibited that the augmentation of CR and load led to increasing the energetic-exergetic efficiency values for each fuel. In this regard, the highest energetic efficiencies for D100, MP5, and MP10 were calculated to be 35.28 %, 31.79 %, and 30.56 %, respectively at the maximum load and CR; meanwhile, the highest exergetic efficiencies were found to be 33.06 %, 29.81 %, and 28.63 %, respectively. At the aforementioned operating conditions, the exergy destruction was found to be 8.33 kW for D100, 10.00 kW for MP5, and 10.65 kW for MP10. The outcomes achieved from the analyses highlighted that the CI engine powered by MP5 and MP10 fuel blends caused similar trends with diesel fuel. Owing to the higher exergetic efficiency of D100, the maximum results in the sustainability index were found to be 1.49 at the most elevated operational conditions. For that reason, methanol/diesel fuel blends including 1-pentanol as a co-solvent will be evaluated to be an alternative fuel instead of traditional diesel fuel when some of the disadvantages are shortly removed. These disadvantages come to mind first and foremost are the costs of methanol and pentanol. The increase in production quantities and the increase in academic studies on this subject will overcome this problem in a short time.

Optimizing biodiesel blends with green hydrogen fuel: A study on combustion duration, fuel mass burnt, engine performance and emissions

Although the combustion of petroleum-based fuels currently satisfies the majority of our energy needs, rapid industrialization has spurred the utilization of alternative energy sources to meet the growing demand for electricity. With the global population on the rise and increasing awareness of the dangers of climate change, there is a greater need to find sustainable and eco-friendly fuels. Utilizing biodiesel derived from non-edible sources is the most efficient and appealing option for meeting energy needs while mitigating environmental impacts. This paper focuses on the preparation and experimental analysis of biodiesel from Karanja oil. Various blends of Karanja biodiesel and regular diesel were produced and stirred to create KB10 (Diesel 90% + Karanja Biodiesel 10%) and KB20 (Diesel 80 % + Karanja Biodiesel 20%). Hydrogen was incorporated into the biodiesel to enhance fuel characteristics, delivered at a rate of 5 L per minute. The emissions and combustion results of the biodiesel blends were compared to those of pure diesel. At full load condition, KB10H5 reported the minimum combustion duration of 25.8°CA with mass fraction burnt of 17.8%. However, the biodiesel blend with 10% and 20% reported the reduced BTE. Highest brake power has been observed at 4.95 kW. The combination of Karanja biodiesel and hydrogen improves fuel quality and reduces the harmful gases emissions such as carbon monoxide and carbon dioxide. It is crucial to ensure that the operation is both efficient and comfortable, and this approach achieved both objectives. In addition, hydrogen energy can also be applied to the railway transportation industry, as a new direction for the green and low-carbon development of intercity transportation, driving the virtuous cycle and innovative development of the hydrogen energy-related industrial chain.

Therapeutic Targets of Tumor Metabolism

Tumor cell metabolism has certain distinctive features such as aerobic glycolysis, utilization of alternative energy sources, increased lipid synthesis, mitochondrial dysfunction, macropinocytosis, autophagy, high levels of ROS, tumor microenvironment and hypoxia. This heterogeneity is determined by the malignant phenotype and the environmental conditions. Targeting specific metabolic pathways may be a promising treatment to increase the overall survival. This paper demonstrates the metabolic reprogramming as the potential anticancer strategy.

The Impacts of Land Use Land Cover Dynamics on Land Management. The Case Study of Adama Zuria District, Oromia Region, Ethiopia

The surface of the earth is undergoing rapid land-use/land-cover (LULC) changes due to various socio-economic activities and natural phenomena. The aim of this research paper was to assess the impacts of the Land Use/Land Cover Changes (LU/LCC) on land management over the period 1989-2017 in the Adama Zuria District. Due to rapid population growth: the expansion of the settlement, agricultural expansion, illegal transaction of the land and degradation of natural resources are the most visible socio-economic and land management problem in the study area. The analysis result of the study showed that in 1989 most of the study area had been covered by farmland and shrub land. In the period between1989 and 2017, cultivated land, plantation and settlement showed incremental changes by (+72.78), (+10.16) and (+48.95) km 2 respectively. While, shrub land and bare land decreased by (-89.65) and (-42.64) km 2 , respectively. On the other hand, the socio-economic survey result reviled the above result, which showed that bare land and shrub land decreased, but, cultivated land, settlement and plantation increased in the specified time. Expansion of agricultural land, population growth and the associated demand for land were the major driving forces for the observed LU/LCC changes in the study area. The impacts of LU/LCC on land management were in term of environmental deterioration, problem related to land use planning (urban and rural), meaning expansion of the illegal settlement and tenure insecurity. Hence, land management practices, utilization of alternative energy sources and family planning education are some of the appropriate interventions to reduce this dramatic change. Keywords : Remote Sensing, GIS, LU/LCC, land tenure, land management. DOI: 10.7176/JEES/11-5-01 Publication date: May 31 st 2021

Vaginal metabolome: towards a minimally invasive diagnosis of microbial invasion of the amniotic cavity in women with preterm labor

Microbial invasion of the amniotic cavity (MIAC) is only identified by amniocentesis, an invasive procedure that limits its clinical translation. Here, we aimed to evaluate whether the vaginal metabolome discriminates the presence/absence of MIAC in women with preterm labor (PTL) and intact membranes. We conducted a case-control study in women with symptoms of PTL below 34 weeks who underwent amniocentesis to discard MIAC. MIAC was defined as amniotic fluid positive for microorganisms identified by specific culture media. The cohort included 16 women with MIAC and 16 control (no MIAC). Both groups were matched for age and gestational age at admission. Vaginal fluid samples were collected shortly after amniocentesis. Metabolic profiles were analyzed by nuclear magnetic resonance (NMR) spectroscopy and compared using multivariate and univariate statistical analyses to identify significant differences between the two groups. The vaginal metabolomics profile of MIAC showed higher concentrations of hypoxanthine, proline, choline and acetylcholine and decreased concentrations of phenylalanine, glutamine, isoleucine, leucine and glycerophosphocholine. In conclusion, metabolic changes in the NMR-based vaginal metabolic profile are able to discriminate the presence/absence of MIAC in women with PTL and intact membranes. These metabolic changes might be indicative of enhanced glycolysis triggered by hypoxia conditions as a consequence of bacterial infection, thus explaining the utilization of alternative energy sources in an attempt to replenish glucose.

Adaptive resource management strategies in paper and pulp industry: a discrete-event simulation approach

In Paper and Pulp (P&P) industry resource management scenarios, such as processing cell(s) efficiency reduction, equipment break-down or failures, alternative energy source (biomass and solar energy) utilization/ synchronization with regular energy sources and management decided change in production rate or product quality often occur in industrial processes causing material flow disruption, energy and production losses. In such scenarios, immediate and appropriate actions are required to be taken to minimize energy and production losses. Emerging resource management options tackle these issues through four different ways i.e., by mixing of readymade pulp at various processing stages, by varying the percentage of input raw material, by adopting a parallel utilization of alternative energy sources and by switching on/off some processing units or parallel working segments. These ways are implementable with immediate effect, accurately monitorable and their degree of application can be regulated within a wide range, thus denoted as adaptive solutions.This research work proposes a discrete-event simulation based real-time resource management technique for paper and pulp industry, wherein some resource management challenges are addressed and solved strategically with adaptive solutions. The presented examples validate that using the developed approach, the effective adaptive strategy can be timely planned to resolve occasionally or permanently happening resource management challenges ensuring an un-interrupted material flow throughout the plant along with the minimization of productivity and energy losses.

Regulation of V-ATPase Assembly in Nutrient Sensing and Function of V-ATPases in Breast Cancer Metastasis.

V-ATPases are proton pumps that function to acidify intracellular compartments in all eukaryotic cells, and to transport protons across the plasma membrane of certain specialized cells. V-ATPases function in many normal and disease processes, including membrane traffic, protein degradation, pathogen entry, and cancer cell invasion. An important mechanism of regulating V-ATPase activity in vivo is regulated assembly, which is the reversible dissociation of the ATP-hydrolytic V1 domain from the proton-conducting V0 domain. Regulated assembly is highly conserved and occurs in response to various nutrient cues, suggesting that it plays an important role in cellular homeostasis. We have recently found that starvation of mammalian cells for either amino acids or glucose increases V-ATPase assembly on lysosomes, possibly to increase protein degradation (for amino acid homeostasis) or for the utilization of alternative energy sources (during glucose starvation). While regulation of assembly in response to amino acid starvation does not involve PI3K or mTORC1, glucose-regulated assembly involves both PI3K and AMPK. Another important form of V-ATPase regulation is the targeting of the enzyme to different cellular membranes, which is controlled by isoforms of subunit a. We have shown that V-ATPases are localized to the plasma membrane of highly invasive breast cancer cells, where they promote cell migration and invasion. Furthermore, overexpression of the a3 isoform is responsible for plasma membrane targeting of V-ATPases in breast tumor cells leading to their increased invasiveness.

Glutamate as a potential \u201csurvival factor\u201d in an in vitro model of neuronal hypoxia/reoxygenation injury: leading role of the Na+/Ca2+ exchanger

In brain ischemia, reduction in oxygen and substrates affects mitochondrial respiratory chain and aerobic metabolism, culminating in ATP production impairment, ionic imbalance, and cell death. The restoration of blood flow and reoxygenation are frequently associated with exacerbation of tissue injury, giving rise to ischemia/reperfusion (I/R) injury. In this setting, the imbalance of brain bioenergetics induces important metabolic adaptations, including utilization of alternative energy sources, such as glutamate. Although glutamate has long been considered as a neurotoxin, it can also be used as intermediary metabolite for ATP synthesis, and both the Na+/Ca2+ exchanger (NCX) and the Na+-dependent excitatory amino-acid transporters (EAATs) are essential in this pathway. Here we analyzed the role of NCX in the potential of glutamate to improve metabolism and survival of neuronal cells subjected to hypoxia/reoxygenation (H/R). In SH-SY5Y neuroblastoma cells differentiated into a neuron-like state, H/R produced a significant cell damage, a decrease in ATP cellular content, and intracellular Ca2+ alterations. Exposure to glutamate at the onset of the reoxygenation phase attenuated H/R-induced cell damage and evoked a significant raise in intracellular ATP levels. Furthermore, we found that in H/R cells NCX reverse-mode activity was reduced, and that glutamate limited such reduction. All the effects induced by glutamate supplementation were lost when cells were transfected with small interfering RNA against NCX1 and EAAT3, suggesting the need of a specific functional interplay between these proteins for glutamate-induced protection. Collectively, our results revealed the potential beneficial effect of glutamate in an in vitro model of H/R injury and focused on the essential role exerted by NCX1. Although preliminary, these findings could be a starting point to further investigate in in vivo systems such protective effect in ischemic settings, shedding a new light on the classical view of glutamate as detrimental factor.

Benefits of utilizing on-site and off-site renewable energy sources for the single family detached house

Japanese Government is formulating new energy policies in the utilization of alternative energy sources to reduce reliance on nuclear and fossil-powered energy sources. This study shows the numerical evaluation of utilizing alternative energy sources for the demonstration single family detached house. The study shows that utilization of different alternative energy sources both off-site and on-site could reduce the house’s dependency on grid line electricity and fossil fuel. The installation of photovoltaic roof tiles, excess generated electricity could be sold through the feed-in tariff scheme. The utilization of a biomass fuel water heater could reduce the carbon dioxide emission. The combination of photovoltaic roof tiles and solar thermal collector with biomass fueled water heater allows the house to sell excess electricity produced, and eliminates the carbon dioxide emission.

Analysis of the Internal Insulation of Renovated Building

The trend in the new construction or renovation of buildings is based on reducing the energy demand of buildings. The required energy need for heating and provision of a satisfactory condition of the internal environment is determined by theoretical calculations. However, the fact that a building is energy efficient does not yet mean it is environmentally appropriate as well. Therefore, the environmental impact of building materials should also be assessed in their selection.The problem with restoring old buildings is to find the correct way how to restore the building while preserving its historical value. The paper presents an example of the reconstruction of the school building built in the year 1906. Reconstruction of the old building is a unique example of recovery. The modern and traditional techniques were used in the reconstruction. This is the first building in Slovakia, where is the front facade insulated with ecological materials (sheep wool, cork, cellulose, etc.) from the interior side and also utilization of alternative energy sources. Other parts of facade are insulated from the outside, with straw bales and wood fiber boards. Largely it has been preserving the original character of the building.Different types of wall structures are compared in theoretical evaluations. The criteria for the evaluation are the thermal resistance of construction (according to EU standards and norms), the weight of the wall and the environmental impact (according to OI3 methodology).

EXAMINATION OF ENERGY RECOVERY OF BREWERS' SPENT GRAIN II. - BIOLOGICAL PROCESS

Production rate of technologies applied in the food industry can only be economical if energy consumption is specifically reduced simultaneously with increasing the capacities and/or utilization of alternative energy sources gains higher ratio during production. A high proportion of waste forms is produced in food processing technologies. Fiscal and environmental cost of waste handling i.e. transportation, recovery and disposal is often significant. Brewing industry’s most important by-product is the brewers' spent grains (BSG) formed during mashing. Utilization of this product is theoretically solved, it is most frequently sold as animal fodder, however utilization in the energy sector can and should be considered and has promising possibilities. Seeking economic and environmental benefits, this paper analyses the possibilities of energy recovery from brewers’ spent grains through aerobic digestion and anaerobic fermentation.

Sustainable Architecture in Slovakia after the Year 1990

Consciously applied sustainable principles of building emerge in architecture since 1973. The cause was the oil crises. It forced a re-evaluation and an abandonment of the previous energy wasting building concepts and triggered the need to seek a new and more efficient architecture, sources of energy and materials. Years 1973 to 1982 can be described as a period of searching for more efficient building concepts, new energy sources and a radical re-assessment of traditional building technologies and energy sources. The period of utilization of alternative energy sources, mainly from solar power and from wind followed. In the 80s, the economics of the developed countries stabilized, which, to some extent, attenuated the development of ecologically conscious architecture. It ascended to the centre of interest only in the last decade of the 20th century, after the United Nations Conference on Sustainable Development in Rio de Janeiro and the World Congress of the UIA in Chicago in 1993. Sustainability in architecture and construction began to acquire a significant position. Currently, projects and urban complexes implementing ecological ideas are being built while getting a significant attention from critics of architecture. After the year 2000, significant documents exalting sustainable architecture to general principles of building are being issued. Perhaps the most important document adopted at the European level is the European Directive on the Energy Performance of Buildings and the European Strategy 20-20-20.Forming thoughts about sustainability in architecture reached Slovak architectural scene with a slight delay. While in abroad first projects focusing on new sources of energy originated in late 70s of the 20th century, in our territory these thoughts came in the centre of interest only in the 90s. The period before the change of political situation in our country in 1989 can be characterized by numerous discussions and forming thoughts on reducing energy consumption of buildings and on utilizing alternative energy sources. Already in the first half of the 80s interesting projects were designed, but unfortunately they remained just paper projects. However, this beginning of ecologically conscious architecture was the essential for its later development. The decade of the 90s enabled to apply a sustainable design approach more intensely and triggered the construction of various architectural projects. The interest focused mainly on the solar energy and in the late 90s back on traditional natural building materials used in vernacular architecture in the past. The aim to reduce the energy consumption of buildings was the driving force in the construction of first experimental houses and public buildings and also in urban structures. Slovakia took part in international projects, such as Brundtland City Project. Abrupt building boom in our country since the beginning of the new century evolved the market of energy efficient buildings. Monitoring of energy savings, inevitable according to the adopted ambitions of the European Union was the starting point of architectural designs especially of low-energy and passive houses. The usage of traditional natural building material remains still up to date. Except of technologically and materially sophisticated constructions, the uniqueness and the quality of architectural design are currently strongly emphasized. The awards-winning outstanding and sustainable architecture serves as a proof.Up to now, most of sustainability in architecture has been performed on a scale of the object. At present, it transforms to the dimension of a city district. This is what we endeavor also at the Faculty of Architecture, STU in both research and teaching practice, mainly in the sustainable design studio.Current ambitions of the European Union in the constructions of sustainable architecture force us to reflect the progress of sustainable architecture. To achieve these ambitions it is necessary to monitor the development of ecologically conscious architecture in Slovak architectural scene. This is the subject of our research Mapping of ecologically conscious architecture in Slovakia. Partial outcome of this research is the content of our conference paper.DOI: http://dx.doi.org/10.5755/j01.sace.12.3.13001

EXAMINATION OF ENERGY RECOVERY OF BREWERS' SPENT GRAIN I. - CHEMICAL PROCESS

Production rate of technologies applied in the food industry can only be of economical nature if energy consumption is specifically reduced in parallel with increasing the capacities and/or utilization of alternative energy sources gains higher ratio during production. In food manufacturing technologies usually a high proportion of waste/byproduct forms; transportation, recovery and recycling of which involves costs in many cases and simultaneously it also means environmental issues. Beer brewing industry’s most important byproduct is the brewers' spent grains (BSG) which forms during mashing. Utilization of this product is theoretically solved, it is most frequently sold as animal fodder but usage in energy sector also holds promising possibilities. Our study examines the possibilities of energetical recovery of brewers' spent grains by means of chemical processes – such as combustion or pyrolysis – seeking for the economical and environmental advantages.

English

The objective of this research paper was to assess the spatial and temporal Land Use/Land Cover Changes (LU/LCC) in Arsi Negele District. Rapid population growth, agricultural expansion, environmental fluctuations, degradation of natural resource and loss of biodiversity are the most visible socio-economic and environmental problem in the study area. Satellite imagery, ground control point data and household level socioeconomic survey were used to produce land cover maps and explaining the historical trends of the study area. ERDAS Imagine and ArcGIS software was used to accomplish the analysis. The analysis result showed that in 1973 most of the study area had been covered by dense acacia woodland and shrub land. Between 1973 to 1986, cultivated grass and bare land increased by 8.98, 33.9, and 36.5 ha respectively. While, shrub and acacia woodland decreased by 6.17 and 73.21 ha, respectively. Between 1986 and 2010, cultivated acacia woodland and land increased by 15.38, 4.63, and 38.52 ha. However, bare and grass land decreased by 19.23 and 39.3 ha, respectively. Furthermore, the trend and magnitude of LU/LCC between 1973 to 2010 acacia woodland and land decreased by 22.72 and 13.58 ha, but shrub land and cultivated land increased by 22.82 and 13.14 ha. Socio-economic survey result revealed that acacia woodland and shrub land decreased, but cultivated land land and grass land increased in the derg regime. However, currently, natural resource conservation activity has got a great emphasis, thus spatial coverage of acacia woodland has increased. Expansion of agricultural land, population growth and the associated demand for land were the major driving forces for the observed LU/LCC changes in the study area. Therefore, loss of biodiversity, soil degradation, and environmental deterioration are largely the results of LU/LCC. Hence, land resources management practices, utilization of alternative energy sources and family planning education are some of the appropriate interventions to reduce this dramatic change. Key words: Remote sensing, GIS, land use/land cover changes (LU/LCC), accuracy, landsat, imagery.

An experimental study on the CO2–CH4 swap process between gaseous CO2 and CH4 hydrate in porous media

Recently, exhaustion of primary energy sources and increase in the atmospheric CO2 levels have become two major energy challenges of the world; therefore, utilization of alternative energy sources and avoiding the emission of greenhouse gases to the atmosphere are some of the serious problems of this century that should be addressed immediately. Many alternatives are being assessed to solve or at least to cease the negative effects of these issues. Vast amount of methane in the form of gas hydrates is stored in several deep marine sediments and in permafrost region. Therefore, production of methane from hydrates may postpone the former problem for significant period of time. Although several production mechanisms like depressurization, thermal treatment and inhibitor injection have been proposed, recovery of methane from hydrate bearing sediments is still an issue of debate. Also, it is widely believed that CO2 emissions due to fossil fuel combustion and transportation are mainly responsible for the increase in the global temperature level. Therefore, several options are being evaluated to diminish the anthropogenic CO2 emissions like storing the captured CO2 in another domain of the planet for example, the geosphere. At this point, the injection of CO2 into CH4 hydrate bearing sediments deserves particular attention as this technique may enable integration of CO2 storage with production from CH4 hydrates. In this study, gaseous CO2 was injected into the unconsolidated sand pack system which includes 30% methane hydrate saturation at free CH4 excess conditions. After the CO2 injection, cyclic behaviors at the pressure gauges were observed for approximately 6 h that may indicate CH4–CO2 swap within hydrate cages. It was thought that the cyclic behaviors in the pressure gauges indicate CO2–CH4 swap within the hydrate cages. Upward and downward trends in cycles results from the gaseous CH4 that was leaving the cages and gaseous CO2 that was stabilizing the cages respectively. Swap process was confirmed by estimating the gas compositions at the instant of CO2 injection and by measuring via gas chromatography analyses after the swap process. As a result of the swap process, it was estimated that 86.3% of the CO2 filled the hydrate cages. After stabilization, system was left to dissociate for several days and samples taken from the cell at different time intervals were analyzed via gas chromatography in order to gain an insight on hydrate distribution in porous media after the swap process. Analyses showed that, amount of free CO2 in the cell were increasing gradually reached a peak value and then decreased. This suggests that, CH4–CO2 swap process mostly took place at the surface of the system as the injected CO2 initially accumulated at the external part of the unconsolidated sand pack system and the area where the reaction took place was maximum. The results obtained from this research proposed that the injection of gaseous CO2 causes dissociation of methane hydrate also samples that were taken during the dissociation process may give some insight about the probable hydrate distribution at the system.

Repeated bleaching events may result in high tolerance and notable gametogenesis in stony corals: Oculina patagonica as a model

Coral bleaching events (BEs) are occurring in coral reefs worldwide and are expected to become annual, triggered by seasonal changes in water temperature. The stony coral Oculina patag- onica experiences repeated seasonal BEs along the Israeli Mediterranean coast. It thus constitutes a good model for assessing the potential effects of expected repeated BEs on coral physiology. Previous studies have shown that the overlap between bleaching and reproduction seasons in O. patagonica impedes gametogenesis. In the present study, we assessed the effect of bleaching on gametogenesis of populations commonly undergoing repeated seasonal BEs, and compared it with the effect of first and second summer BEs on gametogenesis of a population that has not experienced a summer BE in recent years. Interestingly, we found no differences between bleached and non-bleached colonies in most of the reproductive parameters tested in populations undergoing repeated seasonal BEs. We did find, however, that a population that experienced a summer BE for the first time presented signifi- cantly lower reproductive parameters in bleached colonies when compared to non-bleached colonies. Furthermore, in the following year, such bleached colonies showed an improvement in reproductive performance when compared to the previous year. The remarkable differences in gametogenesis between colonies experiencing first summer BE and those experiencing repeated seasonal BEs may be the result of improved utilization of alternative energy sources. This study pro- vides the first evidence for notable gametogenesis in corals undergoing repeated bleaching, and sug- gests that adjustment processes may increase tolerance levels and may play a role in the ability of corals to overcome the expected repeated BEs.