161 research outputs found
UV DISINFECTION - A METHOD OF PURIFYING WASTEWATER FROM FARMS – A REVIEW
The livestock industry increased significantly globally due to increasing demand for animal products. There are however, growing concerns on the environmental risks, associated with the disposal of untreated livestock wastewater into streams and rivers. Disinfection is considered to be the primary mechanism for the inactivation/ destruction of pathogenic organisms to prevent the spread of waterbornediseases to downstream users and the environment.Water disinfection using ultraviolet light is a newer process that currently has a limited use area [5].The purpose of this paper is to present the ultraviolet disinfection process used for the treatment of waste water
ARTIFICIAL COMPACTION GIVEN BY PENETRATION RESISTANCE IN SOILS WITH DIFFERENTUSE
Heavy agricultural machinery is major cause of one of the processes of soil degradation, compaction, which became a problem of significant proportions, especially on soils with high moisture. Excessive traffic affects soil quality and crop production, and also causes environmental problems.The paper presents the results of research conducted to determine soil compaction on three experimental fields: plot of energy willow, plot of clover and cherry orchard, while different moisture contents represent subfactor. Maximum penetration resistances were recorded at 45 cm depth, where the soil is severely compacted: 3194.5 kPa on the soil cultivated with energy willow, 2984kPa in the orchard, respectively 3069kPa on the plot of clover
Genomics of extreme ecological specialists: multiple convergent evolution but no genetic divergence between ecotypes of Maculinea alcon butterflies.
Biotic interactions are often acknowledged as catalysers of genetic divergence and eventual explanation of processes driving species richness. We address the question, whether extreme ecological specialization is always associated with lineage sorting, by analysing polymorphisms in morphologically similar ecotypes of the myrmecophilous butterfly Maculinea alcon. The ecotypes occur in either hygric or xeric habitats, use different larval host plants and ant species, but no significant distinctive molecular traits have been revealed so far. We apply genome-wide RAD-sequencing to specimens originating from both habitats across Europe in order to get a view of the potential evolutionary processes at work. Our results confirm that genetic variation is mainly structured geographically but not ecologically - specimens from close localities are more related to each other than populations of each ecotype from distant localities. However, we found two loci for which the association with xeric versus hygric habitats is supported by segregating alleles, suggesting convergent evolution of habitat preference. Thus, ecological divergence between the forms probably does not represent an early stage of speciation, but may result from independent recurring adaptations involving few genes. We discuss the implications of these results for conservation and suggest preserving biotic interactions and main genetic clusters
ADVANCED TECHNOLOGIES FOR WASTEWATER TREATMENT BY UV – A REVIEW–
Reclamation and reuse ofwastewater is one of the most effectiveways to alleviatewater resource scarcity.Disinfection plays a key role in reuse of wastewater for eliminatinginfectious diseases.Water disinfection using ultraviolet light is a newer process that currently has a limited use area. Ultraviolet(UV) disinfection is now widely implemented as a tertiary treatment forwastewater reclamation. The purpose of this paper is to present the most representative studies on the use of ultraviolet in wastewater treatment
LIGNOCELLULOSIC BIOMASS PRETREATMENT FOR BIOFUEL PRODUCTION
The energetic crisis of recent years, as well as the increasing greenhouse gas emissions, have created premisesfor identification and exploitation of new, non-polluting and economic energy sources. Thus, have appearedconcerns in the field of biofuel production from renewable materials.Worldwide, biomass is considered the most valuable source of alternative energy to fossil fuels. Lignocellulosic biomass, consisting of agricultural and forest residues, animal manure and energy crops,is considered the main substrate for the production of second-generation biofuels (biogas, bioethanol etc).The main components of lignocellulosic materials are cellulose, hemicelluloses and lignin which is the most recalcitrant component of the plant cell wall (the higher the proportion of lignin, the higher the resistance to chemical and enzymatic degradation).In this paper there are presented the main pretreatment methods of lignocellulosic biomass, including mechanical, biological, chemical and thermal pretreatment, with the focus on the principles, advantages and disadvantagesof each method for biofuelsproduction.
The genome sequence of the lesser marbled fritillary, Brenthis ino, and evidence for a segregating neo-Z chromosome
This is the final version. Available on open access from Oxford University Press via the DOI in this recordData availability:
Supplementary Table 1 contains the metadata for the four individuals used for this project. The genome assembly, gene annotation, and raw sequence data can be found at the European Nucleotide Archive under project accession PRJEB49202. The scripts used for analyzing HiC data (chomper.py and HiC_view.py), the script used for calculating site degeneracy (partition_cds.py), and the script used for visualizing synteny (busco2synteny.py) can be found at the following github repository: https://github.com/A-J-F-Mackintosh/Mackintosh_et_al_2022_Bino. The mitochondrial genome sequence and the TE annotation can be found at the same repository.The lesser marbled fritillary, Brenthis ino (Rottemburg, 1775), is a species of Palearctic butterfly. Male Brenthis ino individuals have been reported to have between 12 and 14 pairs of chromosomes, a much-reduced chromosome number than is typical in butterflies. Here, we present a chromosome-level genome assembly for Brenthis ino, as well as gene and transposable element annotations. The assembly is 411.8 Mb in length with a contig N50 of 9.6 Mb and a scaffold N50 of 29.5 Mb. We also show evidence that the male individual from which we generated HiC data was heterozygous for a neo-Z chromosome, consistent with inheriting 14 chromosomes from one parent and 13 from the other. This genome assembly will be a valuable resource for studying chromosome evolution in Lepidoptera, as well as for comparative and population genomics more generally
ADVANCED METHODS OF BIOGAS PURIFICATION – A REVIEW
One of the main environmental problems of today’s society is the continuously increasing production of organic wastes. The discovery of abundant natural gas resources has greatly increased the study of using methane as a feed stock to produce transportation fuels. Biogas (primarily containing methane and carbon dioxide), which is generated from biomass or organic waste via anaerobic digestion or from landfills, is regarded as a renewable source of methane, and has the potential to achieve sustainable production of transportation fuels. Since biogas also contains a significant amount of impurities (e.g.,hydrogen sulphide, ammonia, water vapor and siloxane), a procedure is generally required to clean it before its final use.In this paper are presented the advanced methods of biogas purification
TECHNICAL CONSIDERATIONS REGARDING TO HARVESTING PATATOES AND CARROTS EQUIPMENT
Potatoes and carrots are two plants of great importance in human life. The two vegetables are grown on increasingly large surfaces, which have led to the need to mechanize their planting, maintenance and harvesting technologies. In the continuation of the material, we will find some types of potato, carrot and root crops for both small surfaces and large and very large surfaces.The harvesting technologies of the two plants are similar, so for the types of potato or carrot picking machines (beet, onions, etc.) and leaves the crop on the furrow, the same type of machine can be used. The diversity of these harvesters is very high from one-row or two-row universal trailed to self-propelled harvesters specialized in harvesting a particular crop, which, through a single pass, can do all of the following: dislocation the harvesting material, sorting, collecting and loading them directly into containers, transport trailers or in their own hoppers with automatic downloading capabilities
Unprecedented within-species chromosome number cline in the Wood White butterfly Leptidea sinapis and its significance for karyotype evolution and speciation
Background: Species generally have a fixed number of chromosomes in the cell nuclei while between-species differences are common and often pronounced. These differences could have evolved through multiple speciation events, each involving the fixation of a single chromosomal rearrangement. Alternatively, marked changes in the karyotype may be the consequence of within-species accumulation of multiple chromosomal fissions/fusions, resulting in highly polymorphic systems with the subsequent extinction of intermediate karyomorphs. Although this mechanism of chromosome number evolution is possible in theory, it has not been well documented. Results: We present the discovery of exceptional intraspecific variability in the karyotype of the widespread Eurasian butterfly Leptidea sinapis. We show that within this species the diploid chromosome number gradually decreases from 2n = 106 in Spain to 2n = 56 in eastern Kazakhstan, resulting in a 6000 km-wide cline that originated recently (8,500 to 31,000 years ago). Remarkably, intrapopulational chromosome number polymorphism exists, the chromosome number range overlaps between some populations separated by hundreds of kilometers, and chromosomal heterozygotes are abundant. We demonstrate that this karyotypic variability is intraspecific because in L. sinapis a broad geographical distribution is coupled with a homogenous morphological and genetic structure. Conclusions: The discovered system represents the first clearly documented case of explosive chromosome number evolution through intraspecific and intrapopulation accumulation of multiple chromosomal changes. Leptidea sinapis may be used as a model system for studying speciation by means of chromosomally-based suppressed recombination mechanisms, as well as clinal speciation, a process that is theoretically possible but difficult to document. The discovered cline seems to represent a narrow time-window of the very first steps of species formation linked to multiple chromosomal changes that have occurred explosively. This case offers a rare opportunity to study this process before drift, dispersal, selection, extinction and speciation erase the traces of microevolutionary events and just leave the final picture of a pronounced interspecific chromosomal difference
Studies on metal-organic frameworks of Cu(II) with isophthalate linkers for hydrogen storage
Hydrogen (H2) is a promising alternative energy carrier due to its environmental benefits, high energy density and its abundance. However, development of a practical storage system to enable the “Hydrogen Economy” remains a huge challenge. Metal-organic frameworks (MOFs) are an important class of crystalline coordination polymers constructed by bridging metal centers with organic linkers, and show promise for H2 storage due to their high surface area and tuneable properties. We summarize our research on novel porous materials with enhanced H2 storage properties, and describe frameworks derived from 3,5-substituted dicarboxylates (isophthalates) that serve as versatile molecular building blocks for the construction of a range of interesting coordination polymers with Cu(II) ions.
A series of materials has been synthesised by connecting linear tetracarboxylate linkers to {Cu(II)2} paddlewheel moieties. These (4,4)-connected frameworks adopt the fof-topology in which the Kagomé lattice layers formed by {Cu(II)2} paddlewheels and isophthalates are pillared by the bridging ligands. These materials exhibit high structural stability and permanent porosity, and the pore size, geometry and functionality can be modulated by variation of the organic linker to control the overall H2 adsorption properties. NOTT-103 shows the highest H2 storage capacity of 77.8 mg g−1 at 77 K, 60 bar among the fof-type frameworks. H2 adsorption at low, medium and high pressures correlates with the isosteric heat of adsorption, surface area and pore volume, respectively.
Tri-branched C3-symmetric hexacarboxylate ligands with Cu(II) give highly porous (3,24)-connected frameworks incorporating {Cu(II)2} paddlewheels. These ubt-type frameworks comprise three types of polyhedral cage: a cuboctahedron, truncated tetrahedron and a truncated octahedron which are fused in the solid state in the ratio 1:2:1, respectively. Increasing the length of the hexacarboxylate struts directly tunes the porosity of the resultant material from micro- to mesoporosity. These materials show exceptionally high H2 uptakes owing to their high surface area and pore volume. NOTT-112, the first reported member of this family reported, adsorbs 111 mg g−1 of H2 at 77 K , 77 bar. More recently, enhanced H2 adsorption in these ubt-type frameworks has been achieved using combinations of polyphenyl groups linked by alkynes to give an overall gravimetric gas capacity for NU-100 of 164 mg g−1 at 77 K, 70 bar. However, due to its very low density NU-100 shows a lower volumetric capacity of 45.7 g L-1 compared with 55.9 g L-1 for NOTT-112, which adsorbs 2.3 wt% H2 at 1 bar, 77K. This significant adsorption of H2 at low pressures is attributed to the arrangement of the {Cu24(isophthalate)24} cuboctahedral cages within the polyhedral structure. Free metal coordination positions are the first binding sites for D2, and in these ubt-type frameworks there are two types of Cu(II) centres, one with its vacant site pointing into the cuboctahedral cage and another pointing externally. D2 molecules bind first at the former position, and then at the external open metal sites. However, other adsorption sites between the cusp of three phenyl groups and a Type I pore window in the framework are also occupied.
Ligand and complex design feature strongly in enhancing and maximising H2 storage, and, although current materials operate at 77 K, research continues to explore routes to high capacity H2 storage materials that can function at higher temperatures
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