Water Cages Research Articles

Characteristic Of Environmental Sanitation in Family With Stunting Children Under Five Years Of Age

Attention to malnutrition has increased in recent decades, one of which is stunting. The nutritional problem that is currently being highlighted in the world is stunting where there are around 161 million children experiencing stunting. Stunting is a measure of short height compared to age. Factors causing stunting consist of direct and indirect causes, one of which is from the aspect of environmental sanitation, namely access to clean water, sanitation and hygiene. This study aims to provide an overview of the characteristics of environmental sanitation in families with stunting children under five years of age in the Klatak and Wonosobo Public Health Centers, Banyuwangi. This research is a descriptive study and a case series design. The research subjects used were 60 stunting toddlers with proportional random sampling as the sampling technique. The variables in this study were environmental sanitation, which consisted of access to clean water, ownership of clean water facilities, ownership of bathrooms, ownership of latrines, and ownership of cattle pens. The research instrument used a questionnaire to measure the characteristics of respondents and environmental sanitation conditions, interview guidelines, observation sheets, KIA books, and weighing month reports. The data was processed using descriptive analysis. The results depicted in this study are that most of the research subjects live in families that have access to clean water, have bathrooms and latrines, but also in families who have cattle pens close to the main house. Monitoring of ownership, use, and maintenance of access to clean water, latrines, bathrooms, and livestock cages in the home environment must be carried out properly so that it can become one of the strategies in preventing stunting under five. Prevention of contamination of water, soil, and air quality is one of the ways in preventing stunting in toddlers so that toddlers can develop optimally according to their age and growth period.

Experimental Characterization of Memory Effect, Anomalous Self-Preservation and Ice-Hydrate Competition, during Methane-Hydrates Formation and Dissociation in a Lab-Scale Apparatus

This study explores the process of methane hydrate formation and dissociation in a small-scale confined environment and in the presence of a porous sediment. The research is focused on answering the shortage of information about the intrinsic properties of the hydrate formation and dissociation processes, such as memory effect and anomalous self-preservation, in a lab-scale apparatus. Experiments were carried out consecutively and with the same gas–water mixture. The temperature reached during dissociation was high enough to ensure the complete dissolution of water cages. At the same time, it was sufficiently low to keep the system able to retain the memory of the previous formation of hydrates. Different well-known phenomena were observed and described; memory effect, anomalous self-preservation and competition between ice and hydrates were shown in detail. Experiments confirmed that the memory effect improves the process mainly during the initial nucleation phase, while it does not provide significant changes in the following massive growth phase. Finally, experiments proved that the formation process can be divided in two different steps: the initial intense growth, due to the small difference in local equilibrium conditions, and the subsequent asymptotic growth, which continues until the process is completed.

Crystal Structure and Guest Distribution of N2O Hydrate Determined by Powder X-ray Diffraction Measurements

Research and development of control technology of N2O greenhouse gas are crucial for sustainable development. The crystallographic structural model of structure I (sI) for N2O hydrate, with a composition of N2O·6.1H2O and a density of 1.127 g/cm3 at 263 K, was obtained using powder X-ray diffraction data. In addition, the distributions of the disordered N2O molecules in 512 and 51262 host water cages of sI hydrate were explored. N2O in the large 51262 cage had an off-center distribution and it was out-of-plane to the long axis of the cage, and N2O in the small 512 cage had an isotropic distribution around its center. These crystallographic features of the N2O hydrate were identical to those of the CO2 hydrate, and an increase in cage occupancy depending on the formation pressure was observed. The hydrate composition and dissociation kinetics were discussed pertaining to the information required for the gas storage of N2O.

Molecular recognition between bacterial phosphorothioate DNA and sulfur-binding domain (SBD): competition between the water cage and chalcogen-hydrophobic packet.

Bacterial DNA phosphorothioation (PT) physiologically and stereo-specifically replaces a non-bridging oxygen in a phosphate link with a sulfur atom, which can be recognized by a highly conserved sulfur-binding domain (SBD). Here we conducted thermodynamic integration (TI), molecular dynamics simulation, and quantum chemical calculations to decipher the specific molecular interactions between PT-DNA and SBD in Streptomyces coelicolor type IV restriction enzyme ScoMcrA. The TI-calculated binding affinity of (5'-CCGRp-PSGCCGG-3')2 is larger than that of (5'-CCGGCCGG-3')2 by about 7.4-7.7 kcal mol-1. The binding difference dominantly stems from hydration energy of non-phosphorothioate DNA (9.8-10.6 kcal mol-1) in aqueous solution, despite the persistent preference of 2.6-3.2 kcal mol-1 in the DNA-SBD MD simulations. Furthermore, the quantum chemical calculations reveal an unusual non-covalent interaction in the phosphorothioate-binding scenario, where the PS⋯NP165 chalcogen bond prevails the PS⋯HCβ vdW interactions from the adjacent residues H116-R117-Y164-P165-A168. Thus, the chalcogen-hydrophobic interaction pulls PT-DNA into the SBD binding pocket while the water cage pulls a normal DNA molecule out. The synergetic mechanism suggests the special roles of the proline pyrrolidine group in the SBD proteins, consistent with the experimental observations in the X-ray crystallography and structural bioinformatics analysis.

Generalized energy-based fragmentation approach for accurate binding energies and Raman spectra of methane hydrate clusters

Methane hydrates (MHs) play important roles in the fields of chemistry, energy, environmental sciences, etc. In this work, we employ the generalized energy-based fragmentation (GEBF) approach to compute the binding energies and Raman spectra of various MH clusters. For the GEBF binding energies of various MH clusters, we first evaluated the various functionals of density functional theory (DFT), and compared them with the results of explicitly correlated combined coupled-cluster singles and doubles with noniterative triples corrections [CCSD(T)(F12*)] method. Our results show that the two best functionals are B3PW91-D3 and B97D, with mean absolute errors of only 0.27 and 0.47 kcal/mol, respectively. Then we employed GEBF-B3PW91-D3 to obtain the structures and Raman spectra of MH clusters with mono- and double-cages. Our results show that the B3PW91-D3 functional can well reproduce the experimental C−H stretching Raman spectra of methane in MH crystals, with errors less than 3 cm−1. As the size of the water cages increased, the C−H stretching Raman spectra exhibited a redshift, which is also in agreement with the experimental “loose cage−tight cage” model. In addition, the Raman spectra are only slightly affected by the neighboring environment (cages) of methane. The blueshifts of C−H stretching frequencies are no larger than 3 cm−1 for CH4 from monocages to doublecages. The Raman spectra of the MH clusters could be combined with the experimental Raman spectra to investigate the structures of methane hydrates in the ocean bottom or in the interior of interstellar icy bodies. Based on the B3PW91-D3 or B97D functional and machine learning models, molecular dynamics simulations could be applied to the nucleation and growth mechanisms, and the phase transitions of methane hydrates.

Strengthening and weakening of methane hydrate by water vacancies

Gas clathrate hydrates show promising applications in sustainable technologies such as future energy resources, gas capture and storage. The stability of clathrate hydrates under external load is of great crucial to those important applications, but remains unknown. Water vacancy is a common structural defect in clathrate hydrates. Herein, the mechanical characteristics of sI methane hydrates containing three types of water vacancy are investigated by molecular dynamics simulations with four different water forcefields. Mechanical properties of methane hydrates such as tensile strength are dictated not only by the density but also the type of water vacancy. Surprisingly, the tensile strength of methane hydrates can be weakened or strengthened, depending on the adopted water model and water vacancy density. Strength enhancement mainly results from the formation of new water cages. This work provides critical insights into the mechanics and microstructural properties of methane clathrate hydrates under external load, which is of primary importance in the recovery of natural gas from methane hydrate reservoirs. Cited as: Lin, Y., Liu, Y., Xu, K., Li, T., Zhang, Z., Wu, J. Strengthening and weakening of methane hydrate by water vacancies. Advances in Geo-Energy Research, 2022, 6(1): 23-37. https://doi.org/10.46690/ager.2022.01.03

Distortion of the Host Water Cages of Structure I Gas Hydrates: Structural Analysis of C2H4 Hydrate by Powder X-ray Diffraction

This study investigated the crystal structure and composition of C2H4 hydrate, prepared from finely powdered ice and C2H4 gas, using powder X-ray diffraction (PXRD). A crystallographic structural model of C2H4 hydrate, derived using the Rietveld and direct-space methods, shows that the occupancy of the 512 cages is 38%, assuming that the 51262 cages are fully occupied. Furthermore, similar to C2H6 hydrate, the centers of guest molecules (C2H4) lie out of the centers of the equatorial planes of the 51262 cages and near the centers of the 512 cages (carbon atoms are spherically arranged around these cores). However, the 512 and 51262 cages of C2H4 hydrate are larger and smaller, respectively, than the corresponding cages of C2H6 hydrate, despite the fact that C2H4 molecules are slightly smaller than C2H6 molecules. This difference is attributed to the high occupancy of the 512 cages of C2H4 hydrate, which leads to the expansion and concomitant contraction of the 512 and 51262 cages, respectively. Evidently, the relative distortion of the 51262 and 512 cages of the three-dimensional sI hydrate is a crucial factor determining its stability. In addition, the kinetic stability of C2H4 hydrate under low-temperature conditions was investigated by temperature-dependent PXRD.

Kinetic hydrate inhibitor performance and adsorption characteristics of poly(N-alkyl-N-vinyl acetamide)s: A first-principles study

Kinetic hydrate inhibitors (KHIs) have been developed to prevent hydrate plugging of flow lines due to high efficiency and low dosage, but the intrinsic mechanism remains inconclusive and requires further verification. In this work, the inhibition performance of poly(N-alkyl-N-vinyl acetamide)s having varying alkyl side chain lengths has been investigated by the first-principles calculations and simulations. Further, the adsorption properties of these KHIs on various sites of the hydrate surface are considered. The results show that KHIs can adjust their positions and orientations to fit the empty cages, and that the adsorption strength is enhanced by increasing the alkyl side chain length, which is attributed to both hydrogen bonding and hydrophobic interactions. KHIs can drive CH4 away from the hydrae surface, but also can hold the lattice positions of water cages, which is responsible for reducing gas uptake and inhibiting hydrate growth. The molecular properties of KHIs indicate that the chemical reactivity increases with the increase of the alkyl side chain length, leading to the strong adsorption strength between KHIs and the hydrate surface, and thus improve the inhibition performance of KHIs. These results provide not only an important understanding of the KHI inhibition mechanism but also a basis for designing high efficient KHIs.

Methane and carbon dioxide hydrates properties in presence of Inconel 718 particles: Analyses on its potential application in gas separation processes to perform efficiency improvement

Methane and carbon dioxide hydrates were formed in a small-scale experimental apparatus and in presence of a pure-quartz porous sediment impregnated with Inconel 718 particles produced via gas atomization and destined to additive manufacturing applications. The aim of this work consisted in exploring for the first time the effect of such material, commonly used in additive manufacturing, for gas hydrates production, in order to detect its properties in this field and its potential applications. Three In concentrations were tested: 8.68, 17.36 and 26.04 wt%. Multiple tests were carried out for both the guest compounds considered. This compound was found to act as promoter for the process in presence of methane and inhibitor in presence of carbon dioxide. In particular, at temperatures ranging from 2.1° to 6.5 °C and with 26.04 wt% In, CO2 molecules required higher pressure than CH4 molecules for being trapped into water cages. Because CO2 hydrates naturally form at milder thermodynamic conditions than CH4 hydrates, the existence of a narrow thermodynamic region, with this reverse property, was highlighted for being suitably exploited to improve the efficiency of CO2/CH4 mixture separation via hydrates formation.

Adsorption behavior of kinetic inhibitors on hydrate surfaces and its relation to the inhibition performance

Adsorption behavior of poly(N-vinyl alkanamide)s with varying alkyl side chains on hydrate surfaces and its relation to the kinetic hydrate inhibition performance has been studied by the first-principles method. The results show that inhibitors are strongly adsorbed on the hydrate surface, because of hydrogen bonding and hydrophobic interactions, and then disrupt the water cage structure. As the alkyl side chain increases, the adsorption affinity of inhibitors increases, in accordance with the trend of experimental inhibition efficiencies. Structure and electronic property analysis indicates that the adsorption affinity of inhibitors correlates strongly with their molecular reactivity.

Stocking density matters in open water cage culture: Influence on growth, digestive enzymes, haemato-immuno and stress responses of Puntius sarana (Ham, 1822)

A 90 days trial was carried out to investigate the impact of stocking density on growth performances and the health status of Puntius sarana in inland open water cages (Salia Dam of Odisha, India). The fishes of mean body weight 32.04 ± 1.25 g were stocked @ three stocking densities (SD) i.e., 10 m−3 (SD10), 20 m−3 (SD20), and 30 m−3 (SD30) and fed with commercial feed of 28% protein and 4% fat. The growth, in terms of weight gain, specific growth rate, absolute growth rate, percentage survival, protein efficiency ratio, and feed conversion efficiency was significantly decreased (P < 0.05) with increment in stocking density, however the lowest feed conversion ratio (FCR) was obtained in SD10 (1.68 ± 0.02). At the end of the experiment, a significant increase in red blood cells, haemoglobin, haematocrit, and platelets level was found in SD30, while white blood cells were showed a reverse trend. The concentration of superoxide dismutase, catalase, serum glucose, serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), and cortisol were increased significantly in SD30. On contrary, the level of serum triiodothyronine and thyroxine decreased with an increase in stocking density. The higher stocking density negatively affected the amylase activity without any adverse impact on protease and lipase. The cluster analysis revealed that SD20 and SD30 came under the same dendrogram while SD10 formed a separate one. The outcome of PCA (Principal Component Analysis) revealed that increased levels of SGPT, SGOT, glucose, and cortisol negatively influenced the growth attributes. Stocking density up to 20 fingerlings m−3 of P. sarana in inland open water cages performed ideally in terms of growth and health status of fish.

Penyuluhan pentingnya pelestarian ekosistem Danau Timbang Bunga Pengantin di Desa Sungai Sorik Kecamatan Kuantan Hilir Seberang Kabupaten Kuantan Singingi

Oxbow lake ecosystem have been used by local people traditionally along with the human history. The ecosystem were of important for clean water resources, fishing and cage culture, collecting aquatic fauna as well as rice field. However, more intense human intervention has brought about recently an effect on the sustainability of the ecosystem in term of ecological, social economical perspective. Danau Timbang Bunga Pengantin of Sungai Sorik, were developed for tourist destination especially for water attraction activities, floating restaurant, and fish cage culture. As such, the ecological burden stressors increased significantly. The present study aimed at promoting awareness and participation of local people on conservation and protection of the ecosystem from unsustainable uses, by attending group extension in classroom and observation outdoor. The results showed that 60% of the community were just aware of the effect of certain activities done to the sustainability of the lake. Responses of the participants in the classroom categorized high and curious to participate on the conservation of the lake.

Leptospirosis Transmission in Ponorogo District of East Java, Indonesia

This study aims to identify Leptospira bacterial infection in livestock owners and their livestock, as well as to examine potential risk factors correlated with the incidence. 50 participants were selected and their blood samples were collected. 50 urine samples were collected from livestock owned by the participants. Polymerase Chain Reaction (PCR) was used to identify the existence of the Leptospira bacteria. The questionnaire instrument was used to obtain information about individual characteristics and hygiene. The Chi-Squared test was adopted to examine the correlation between outcome and explanatory variables. The confirmation PCR test detected the bacterial DNA in 2 out of 50 blood samples examined (4%) and 3 out of 50 urine samples examined (6%). Human leptospirosis incidence is significantly correlated with occupation type (p=0.035), personal protective equipment (PPE) use (p=0.044), water puddle contact (p=0.044), cage sanitation (p=0.044) and Leptospira bacteria presence in livestock urine (p=0.007). Insignificant correlation was showed in owners’ age variable. The presence of Leptospira bacteria both in livestock and the owners indicates the real threat of animal to human transmission. Further study with larger sample size and wider range variables and meticulous examination technique is required to comprehend the investigation.

Leptospirosis Transmission in Ponorogo District of East Java, Indonesia

This study aims to identify Leptospira bacterial infection in livestock owners and their livestock, as well as to examine potential risk factors correlated with the incidence. 50 participants were selected and their blood samples were collected. 50 urine samples were collected from livestock owned by the participants. Polymerase Chain Reaction (PCR) was used to identify the existence of the Leptospira bacteria. The questionnaire instrument was used to obtain information about individual characteristics and hygiene. The Chi-Squared test was adopted to examine the correlation between outcome and explanatory variables. The confirmation PCR test detected the bacterial DNA in 2 out of 50 blood samples examined (4%) and 3 out of 50 urine samples examined (6%). Human leptospirosis incidence is significantly correlated with occupation type (p=0.035), personal protective equipment (PPE) use (p=0.044), water puddle contact (p=0.044), cage sanitation (p=0.044) and Leptospira bacteria presence in livestock urine (p=0.007). Insignificant correlation was showed in owners’ age variable. The presence of Leptospira bacteria both in livestock and the owners indicates the real threat of animal to human transmission. Further study with larger sample size and wider range variables and meticulous examination technique is required to comprehend the investigation.

Hydrate formation as a method for natural gas separation into single compounds: a brief analysis of the process potential

In both natural gas and petroleum reservoirs, the extracted gas is not only composed of methane: a variable and significant quantity of other compounds, such as different hydrocarbons (ethane, butane, pentane, propane, etc.), inert gas (nitrogen), and toxic and corrosive molecules (i.e., carbon dioxide and hydrogen sulfide), are present. In order to reach commercial specifications, natural gas has to be treated, in particular for reaching the minimum gross calorific value required and decreasing CO2 and H2S presence under the respective tolerance values. To do this, several different treatments are commonly applied, like inlet separation, sweetening, mercury removal, dehydration, liquid recovery, and, finally, compression for its transportation. Considering the growing demand and the necessity of exploiting also lower quality natural gas reservoirs, in the present paper, an original solution, for performing a gas treatment, is proposed and analyzed. It consists of promoting hydrates formation for both different compounds separation and gas storage. The greatest part of chemicals commonly present in natural gas is capable to form hydrates, but at different thermodynamic conditions than others. Parameters such as the typology of stored compound and the formation process efficiency are mainly related to partial pressure of each element. Here, the present strategy has been explored and the results achievable were shown. In particular, different possible natural gas compositions were taken into account and specifications required for gas commercialization were considered target of the process. Results led to different possibilities of raw gas treatment: in some cases, gas separation led to contemporary CH4 storage into hydrate structures, while, in the presence of different mixture compositions, contaminants were trapped into water cages and methane (and, eventually, other hydrocarbon compounds) remained in the gas phase.

Homogenous nucleation rate of CO2 hydrates using transition interface sampling.

Carbon dioxide and water can form solid clathrate structures in which water cages encapsulate the gas molecules. Such hydrates have sparked much interest due to their possible application in CO2 sequestration. How the solid structure forms exactly from the liquid phase via a homogenous nucleation process is still poorly understood. This nucleation event is rare on the molecular timescale even under moderate undercooling or supersaturation conditions because of the large free energy barrier toward crystallization, rendering a brute force simulation of hydrate nucleation unfeasible for moderate undercooling or supersaturation. Here, we perform transition interface sampling simulations to quantify the homogenous nucleation rate for CO2 hydrate formation using accurate atomistic force fields at 500 bars for three different temperatures between 260 and 273 K. Collecting more than 100 000 pathways comprising roughly two milliseconds of simulation time, we computed a nucleation rate in the amorphous phase of ∼1021 nuclei s-1 cm-3 for a temperature of 260 K and a rate of ∼1012 nuclei s-1 cm-3 for a temperature of 265 K. For a temperature of 273 K, we find that the hydrate forms an sI crystalline phase with a rate of order of ∼101 nuclei s-1 cm-3. We compare these rates to classical nucleation theory estimates as well as experiments, and to nucleation rate estimates for methane hydrates and discuss possible causes of the observed differences. Our findings shed light on the kinetics of this important clathrate and should assist in future hydrate formation investigation.

Infrared spectroscopy of clathrate hydrates for planetary science: the ethylene case

ABSTRACT Hydrocarbons are observed in the gas or solid phases of Solar system objects, including comets, Trans-Neptunian Objects, planets, and their moons. In the presence of water ice in these environments, hydrocarbons-bearing clathrate hydrates could form. In clathrate hydrates, guest molecules are trapped in crystalline water cages of different sizes, a phase used in models of planetary (sub-)surfaces or icy bodies such as comets. The phases in presence, the potential estimate of abundances of hydrocarbon species, and the spectroscopic behaviour of hydrocarbon species in the different phases must be recorded to provide reference spectra for the comparison with remote observations. We show in this study the specific encaged ethylene signatures, with bands similar in position, but shifted from the pure ethylene ice spectrum. They show a marked temperature dependence both in position and width. Some vibrational modes are activated in the infrared by interaction with the water ice cages.

The main diseases of African clary catfish when grown in closed water supply installation and cage farms

In this paper, an analysis of the literature on the diseases of Clarias catfish (Clarias gariepinus) carried out. The main bacterial, parasitological and viral diseases that are characteristic of the soma under the conditions of a recirculating aquaculture system have identified. In addition to this, a study of the pathogenic microflora of the Claria catfish carried out. Crops of biological material showed the presence of pathogenic genera such as Acinetobacter ssp., Pseudomonas Fluorescens, Aeromonas Hydrophilia, as well as opportunistic species: Eikenella sp. and Salmonella sp., whose virulence for C. Gariepinus has not confirmed.

A Brief Overview of Lab - Scale Apparatuses Used in the Recent Years for Experimental Investigations on Gas Hydrates

Gas hydrates are nonstoichiometric solid crystalline compound, whose formation is function of several parameters, such as pressure, temperature, fluid phase composition, reservoir saturation degree and others. One of the most critical aspects related to the research on this manner stays in differences existing between experimental results reached by using different experimental apparatuses. Moreover, laboratory scale reactors often have very contained dimensions with a consequent increasing influence of the boundary conditions. In the present paper, a brief overview of reactors used worldwide for experimental research on gas hydrates formation, is provided. In particular, the surface/volume ratio was calculated for each different typology of reactor and then associated with the ratio between moles of guest compound entrapped into water cages and moles injected. Even if such ratio does not represent the process efficiency, it is proportional to it. Consequently, that comparison was useful to well define the supporting effect of a greater S/V ratio on the hydrate formation process efficiency.

Random-Phase Approximation in Many-Body Noncovalent Systems: Methane in a Dodecahedral Water Cage.

The many-body expansion (MBE) of energies of molecular clusters or solids offers a way to detect and analyze errors of theoretical methods that could go unnoticed if only the total energy of the system was considered. In this regard, the interaction between the methane molecule and its enclosing dodecahedral water cage, CH4···(H2O)20, is a stringent test for approximate methods, including density functional theory (DFT) approximations. Hybrid and semilocal DFT approximations behave erratically for this system, with three- and four-body nonadditive terms having neither the correct sign nor magnitude. Here, we analyze to what extent these qualitative errors in different MBE contributions are conveyed to post-Kohn-Sham random-phase approximation (RPA), which uses approximate Kohn-Sham orbitals as its input. The results reveal a correlation between the quality of the DFT input states and the RPA results. Moreover, the renormalized singles energy (RSE) corrections play a crucial role in all orders of the many-body expansion. For dimers, RSE corrects the RPA underbinding for every tested Kohn-Sham model: generalized-gradient approximation (GGA), meta-GGA, (meta-)GGA hybrids, as well as the optimized effective potential at the correlated level. Remarkably, the inclusion of singles in RPA can also correct the wrong signs of three- and four-body nonadditive energies as well as mitigate the excessive higher-order contributions to the many-body expansion. The RPA errors are dominated by the contributions of compact clusters. As a workable method for large systems, we propose to replace those compact contributions with CCSD(T) energies and to sum up the remaining many-body contributions up to infinity with supermolecular or periodic RPA. As a demonstration of this approach, we show that for RPA(PBE0)+RSE it suffices to apply CCSD(T) to dimers and 30 compact, hydrogen-bonded trimers to get the methane-water cage interaction energy to within 1.6% of the reference value.