Fresh Sea Research Articles

Summary of the Test Methods for Icing Strength of Freshwater and Seawater

Polar navigation ships, offshore platforms, and amphibious aircraft sometimes need to work in low temperature environments, which will inevitably form varying degrees of icing on the surface of structures such as cabin doors. In order to ensure their normal working conditions, it is advisable to choose reasonable anti-icing and deicing methods to prevent icing or effectively remove icing. Therefore, it is necessary to study the mechanical properties of ice to provide a reference for the selection of anti-deicing methods. This article summarizes the common methods for measuring the shear strength and tensile strength of ice, which can provide some guidance for the freezing strength test of fresh water and sea water.

Effect of irrigation salinity and ecotype on the growth, physiological indicators and seed yield and quality of Salicornia europaea

The euhalophyte species Salicornia europaea is cultivated for oilseed and as a fodder crop in various parts of the world. In saline coastal environments it possesses great potential for the subsistence of the most disadvantaged farmers. We investigated the effect of salinity levels in irrigation water on the germination capacity, shoot biomass and seed productivity as well as diverse quality traits (nitrogen content in shoots and seeds and fatty acids, in seeds) and physiological traits (stable carbon and nitrogen isotopes and ion content) of two accessions collected in the United Arab Emirates (UAE). The three salinity levels tested were irrigation with fresh water (0.3 dS m−1), brackish water (25 dS m−1) and sea water (40 dS m−1). In addition, a hypersaline condition (80 dS m−1) was also tested for germination. The best germination rates were achieved with seeds exposed to fresh and brackish water, while imbibition with sea water decreased germination by half and hypersaline water inhibited it almost totally. However, the best irrigation regime in terms of biomass and seed yield involved brackish water. Moreover, rising salinity in the irrigation increased the stable isotope composition of carbon (δ13C) and nitrogen (δ15N), together with the Na+ and K+ of shoots and seeds, and the lipid levels of seeds, while the total nitrogen content and the profile of major fatty acids of seeds did not change. Differences between the two ecotypes existed for growth and seed yield with the best ecotype exhibiting lower δ13C and higher K+ in both shoots and seeds, lower Na+ and higher δ15N in shoots, and lower N in seeds, together with differences in major fatty acids. Physiological mechanisms behind the response to irrigation salinity and the ecotypic differences are discussed in terms of photosynthetic carbon and nitrogen metabolism.

Myśleć przez morze. Sztrandowanie i inne metafory, w poszukiwaniu poznawczych alternatyw

Thinking Through the Sea. Stranding and Other Metaphors, in Search of Cognitive Alternatives In this article, I would like to consider the comparison of stranding to landcentric cognitive processes that translate into the creation of an impossible world – devoid of water and its potentials, rhythms and cycles immersed in it. I will illustrate this with examples of fresh water and sea hydro-policies (including nuclear trials in the Pacific) and will explore cognitive and activist alternatives proposed by the Polynesian sailors and navigators. I will also use two ambiguous metaphors of a ship and a Polynesian voyaging canoe as an opening for different narrations of the planets’ future in the climate crisis.

КАДМИЙ В ВОДЕ ПО КОНТИНУУМУ «ЭСТУАРИЙ Р. МИУС – ТАГАНРОГСКИЙ ЗАЛИВ АЗОВСКОГО МОРЯ»

We have studied the distribution of concentrations of bulk cadmium, as well as dissolved and suspended forms of its migration, along the continuum ‘the Mius estuary – the Taganrog Bay of the Azov Sea’. Within this area, there are located two barrier zones – the zone of the Mius River waters mixing with the Miussky Liman waters and the zone of the estuary waters mixing with the waters of the Taganrog Bay. In these barrier zones, the concentrations of all forms of cadmium increased significantly, which was due to the high wind activity observed during the study period, as a result of which, the silt deposit was stirred up, and a significant part of the cadmium previously deposited on the geochemical barriers migrated into the water. In general, in the water of the studied continuum, we observed a positive correlation of concentrations of all forms of cadmium not only with each other but also with the values of pH and salinity. For the entire studied system, the dissolved form of cadmium migration slightly prevailed over the suspended form and ranged from 50 to 75% (on average, 57%) of its gross content. At the same time, the absolute content of the dissolved form of cadmium migration did not go beyond the maximum values of the range of its concentrations in fresh surface and sea waters of the globe, as well as the MPC values for the corresponding environments.

Change in business scenario during Covid 19 pandemic

Entrepreneurship development is the means of enhancing the knowledge and skill of entrepreneurs through several classroom coaching and programs, and training. The main point of the development process is to strengthen and increase the number of entrepreneurs. It encourages them to make better judgments and take a sensible decision for all business activities. The year 2020 has witnessed a drastic change in each and every sphere of life which includes business sector also. According to World Health Organization (WHO, 2019) there are several pandemics in the history that has changed the human life. COVID-19 has initiated on 12 Dec 2019 in Wuhan city of China, and it was noticed that people are infected by pneumonia by illusory link to a shop that retails fresh sea food to people. Within week millions of people infected with this virus in China. Furthermore, at the present time 205 countries are infected with this virus and their economies.The coronavirus pandemic has gained massive scale with more than three million cases across the world. The global economy has witnessed a major downfall in business sector due to this pandemic situation. Several countries have imposed stringent measures to contain the transmission of the virus among the masses. India imposed a nationwide lockdown on March 24, which was subsequently extended till May 17.Coronavirus drastically changed the global trends. As the country enters the extended lockdown period with only essential goods being available, businesses have requested employees to work from home, and some have been shut down temporarily. A rapid change has occurred in every business. It has changed the behaviour of human, nature of trading, business and even the way of life. The main aim of my study is to find out various aspects of entrepreneurship development and entrepreneurial scenario during Covid 19.

Analisis Kandungan Nutrisi Pada Produk Nugget Gonad Landak Laut Tripneustes gratilla (Linnaeus 1758)

Tujuan penelitian ini adalah mengidentifikasi kandungan proksimat/nutrisi terhadap produk Nugget gonad landak laut (NUGODA) dari hasil olahan gonad landak laut Tripneustes gratilla segar. Penelitian berlangsung selama tujuh bulan dengan 36 rancangan percobaan, sampel diambil dari daerah Kepulauan Barrang Lompo Makassar. Gonad segar yang didapatkan kemudian dibuat menjadi produk (NUGODA) Tripneustes gratilla setelah itu dianalisis kandungan gizi yang terdapat pada produk (proksimat) dengan metode AOAC. Hasil Penelitian ini menunjukkan nilai kandungan nutrisi dengan 4 perlakuan (A1,A2 ,A3,A4) dimana perbandingan gonad sebanyak (0 g,150 g,200 g,250 g). Didapatkan hasil terbaik kandungan nutrisi pada perlukan A4 dengan penambahan gonat sebanyak 250 g dengan rata-rata kadar protein yang dihasilkan 8.51 %, kadar lemak 5.63 %, Abu 2.13 % dan kadar air 60.37 % dimana hasil yang didapatkan telah memenuhi Standar Nugget Ikan (SNI 7758:2013).

Effects on Microstructure and Corrosion Behavior of a Heat Treated CuZn36Pb2 Brass

The brass CuZn36Pb2 is widely used for fittings, valves and other installation materials. Failures are observed occasionally caused by corrosion. Considering the Cu-Zn phase diagram only α-phase exists in the range of 650 and 300 °C. At higher temperatures α- and β-phase is stable and at lower temperatures α- and β´-phase exist. Since the β-phase is Zn-enriches, it is attacked severely by corrosion. In the recent work brass samples were heat treated at temperatures between 850 and 200 °C to study the microstructural changes and the corresponding electrochemical properties. Potentiostatic corrosion tests were applied in artificial fresh water and sea water at different potential settings. After a heat treated at 850 °C the brass has formed b-phase which can be shown by metallography. At lower temperatures the microstructure is fine grained and no β-phase was observed. To verify the presence of β´-phase a heat treatment at 200 °C was performed but no β´-phase was observed, which was confirmed additionally by X-ray diffraction. Again, after corrosion tests the samples were investigated by metallography and the β-phase was obviously more attacked than the α-phase.

Source Apportionment of Aerosol at a Coastal Site and Relationships with Precipitation Chemistry: A Case Study over the Southeast United States.

This study focuses on the long-term aerosol and precipitation chemistry measurements from colocated monitoring sites in Southern Florida between 2013 and 2018. A positive matrix factorization (PMF) model identified six potential emission sources impacting the study area. The PMF model solution yielded the following source concentration profiles: (i) combustion; (ii) fresh sea salt; (iii) aged sea salt; (iv) secondary sulfate; (v) shipping emissions; and (vi) dust. Based on these results, concentration-weighted trajectory maps were developed to identify sources contributing to the PMF factors. Monthly mean precipitation pH values ranged from 4.98 to 5.58, being positively related to crustal species and negatively related to SO42−. Sea salt dominated wet deposition volume-weighted concentrations year-round without much variability in its mass fraction in contrast to stronger seasonal changes in PM2.5 composition where fresh sea salt was far less influential. The highest mean annual deposition fluxes were attributed to Cl−, NO3−, SO42−, and Na+ between April and October. Nitrate is strongly correlated with dust constituents (unlike sea salt) in precipitation samples, indicative of efficient partitioning to dust. Interrelationships between precipitation chemistry and aerosol species based on long-term surface data provide insight into aerosol–cloud–precipitation interactions.

PM10 chemical composition at a residential site in the western mediterranean: Estimation of the contribution of biomass burning from levoglucosan and its isomers

The composition of PM10, including molecular markers of biomass burning (levoglucosan, mannosan and galactosan), was determined at a residential site in southeastern Spain during winter and early spring. The average PM10 concentration was 25.0 μg m−3, being organic carbon (OC, 6.77 μg m−3), NO3− (2.02 μg m−3), SO42− (1.36 μg m−3) and Ca2+ (1.01 μg m−3) the main components. Levoglucosan was the dominant anhydrosugar (143 ng m−3), accounting for 81% of the total concentration of monosaccharide anhydrides. The average contribution of biomass combustion to OC, estimated from the levoglucosan data, was 23%. This value agreed well with that calculated by Positive Matrix Factorization (PMF, 25%). The PMF model resolved six factors that were assigned to road traffic (28%), secondary aerosols (27%), soil dust (14%), fresh sea salt (13%), aged sea salt (10%) and biomass burning (8%). This model was used to estimate the OC/Levoglucosan and PM10/Levoglucosan emission ratios for the study area.

Conceptual design of a gliding UAV for bird strike prevention and observation

PurposeThe purpose of this paper is to create a conceptual design a bird-inspired unmanned aerial vehicle (UAV) that can stay in the air for a long time while this design influences the species near the airport with predator appearance. To achieve that goal, reverse engineering methods took into account to find out optimal parameter, and effective bird species were examined to be taken as an example.Design/methodology/approachDesign parameters were determined according to the behaviour of bird species in the region and their natural enemies. Dalaman airport where is located near the fresh water supplies and sea, was chosen as the area to run. To keep such birds away from the airport and to prevent potential incidents, information from animal behaviour studies is enormously important. According to Tinbergen, chicken and gees reacted to all short-necked birds because they thought they were predators. The entire method is based on information from these data, along with reverse engineering principles.FindingsUAV can remain in the air for more than 5 min when the engine stops at an altitude of 200 m. Also, when the UAV loses altitude of 100 m, it can cover a distance of about 2 m with the 19.8-glide ratio. Moreover, 380 KV brushless electric motor can provide 5.2 kg thrust force with 17 × 8-inch folding propeller which means 1.3 thrust to weight ratio (T/W). This engine and propeller combination work up to 12 min at maximum power with 7000 mAh lipo-battery. The UAV can climb more than 40 min at 0.2 T/W ratio.Research limitations/implicationsWhile bird-inspired UAV trials have just begun, general ornithopter studies have taken smaller birds as their source because this is the limit of the flapping wing, one of the largest birds modelled in this study. Thus, it is inevitable the UAV influences other birds in the area. In addition, this bird’s inherent flight behaviour, such as soaring, ridge lifting and gliding, will increase its credibility. Owing to size similarity with UAV systems, reverse engineering methods worked well in the design.Practical implicationsSome of the specialist try to fly trained falcon in airport as an alternative method. This study focussed on the design of a bird-inspired UAV by optimizing the glide performance, both for scare the other birds around the airport and for the observation of birds in the vicinity and for the identification of bird species.Social implicationsAs this type of work has been proven to reduce the risk of bird strikes, the sense of flight safety on society will increase.Originality/valueResearchers and companies generally work on flapping wing models for related subjects. However, these products are kind of model of the Falconiformes species which don’t have too much influence on big birds. For this reason, the authors took account of Imperial eagle’s specifications. These birds perform long soaring flights while seeking for prey like the glider design. So, the authors think it is a new approach for designing UAV for preventing bird-strike.

Experimental studies of the effect of sea buckthorn and wheat bran in food on the physiological status of rats

The aim of this research paper was a sanitary-toxicological study of the effectiveness and safety of developed functional property products, such as chopped semi-finished products from chicken with wheat bran and shortbread cake with cottage cheese and sea buckthorn, in preclinical studies on laboratory animals. Methods — The effect of new products on the experimental rats was studied using physiological, biochemical, pathomorphological and histological research methods. As a result, it was discovered that the inclusion of foods with wheat bran and fresh sea buckthorn into the diet of experimental animals had a positive effect on the behavioral reactions of rats, the increase of appetite and the rapid growth of animals. Results — The improvement in the metabolic processes physiology of the studied rats was noted in the biochemical and morphological blood parameters. In the experimental group of rats where carbohydrates were partially substituted with cottage cheese shortbread cake and sea buckthorn, a significant decrease in the total bilirubin content was noted; the level of cholesterol in the blood serum of experimental animals from group which received chicken cutlets with bran was 1.4-1.7 times lower than the cholesterol content in animals of the control and other experimental groups. At the same time, statistically significant differences in the number of red blood cells, white blood cells, platelets and hemoglobin level, the activity of alanine and aspartate aminotransferases, alkaline phosphatase and amylase, the level of total protein and the creatinine content were not revealed in the group of experimental rats compared with the control group of rats, receiving a standard diet. The histological data showed that the liver structure of the experimental animals had a more pronounced beam and capillary structure compared with the control group, and the condition of the villi and epithelium of the small intestine showed the positive physiological effect of the studied herbal additives in food technology with functional properties. Conclusion — The research results allow us to conclude that the developed products are functional, intended for the systematic use in the composition of food rations by all age groups of a healthy population, which reduces the risk of gastrointestinal and liver diseases.

INVENTARISASI HEWAN INVETEBRATA PADA FILUM NEMATHELMINTHES

<p>This journal discusses the theme of the Nemthelminthes phylum. nemathelminthes is a phylum that was once used in the animal kingdom (Animalia). Its members include a variety of worms known as gilig worms: animals with long cylindrical bodies, even so long that the name 'Nemathelminthes' appears. Which means "threadworm" (from Greek). His body is not sprouting. in this phylum, there are two classes, nematodes and nematomorphs. Nematodes have been found in the muscles outside the cells and not epithelial cells. There are no cilia here. An independent living nematode has a compound mouth and several tools and tastes and eyes. Gilig worms that live parasites, their body structure is simpler. The digestive tract is more complete and precisely divided into regions such as the mouth, oral cavity, pharynx, esophagus, small intestine, rectum, and body structure. The larvae live parasites on the human body or arthopoda, and after adulthood these worms live freely in fresh water and sea water.</p>

Comparative Study on the Effect of Cold Atmospheric Plasma, Ozonation, Pulsed Electromagnetic Fields and High-Pressure Technologies on Sea Bream Fillet Quality Indices and Shelf Life

A comparative study on the effect of nonthermal processing using cold atmospheric plasma (CAP), ozonation (OZ), pulsed electromagnetic fields (PEMF) and high pressure (HP) on the quality and shelf life of fresh sea bream fillets was conducted. The aim was the selection of the optimum nonthermal processing technology for minimum effect on the fish quality and maximum shelf-life extension, based on pre-selected processing conditions for each technology. Air plasma was generated using a surface dielectric barrier discharge (SDBD) source (3 kV, 45 kHz) applied for 15 min at 25 °C. PEMF (80 J/pulsed energy, 12.5 mT, 3 Hz) and OZ (1.3 mM of aqueous ozone, flow rate 640 ppm) were also applied for 15 min at 25 °C. HP treatment at 300 MPa/5 min at 25 °C was studied. Processed and unprocessed fillets were stored at 4 °C for 22 days. The fish fillets were analysed for their microbial load, pH, texture, colour, lipid oxidation, and sensorial characteristics, during storage. The shelf life of the product was extended by 4 and 2.5 days after HP and CAP processing, respectively. HP was more effective on the microbial load reduction compared to the other processes; nevertheless, colour and texture alteration of the fish fillets was observed. CAP processing decreased the initial total microbial load by 1.03 logCFU/g, while also resulted to reduced intension of the fish odour. PEMF and OZ affected slightly the quality indices nevertheless found to be less effective on the microbial load reduction with only 1 day shelf-life extension of the fillets.

Antibacterial activity of Stichopus hermanii and Stichopus variegatus methanol extract

Since 500 years ago sea cucumber has been used as wound healing medicine. Sea cucumbers are thought to function as a cell growth factor and have the potential as an antibacterial agent. This study aims to determine whether the methanol extract of sea cucumber has antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa so that it can be used to help diabetic wound healing of people infected with the same bacteria. The extraction method used was maceration with methanol to dried frozen simplicia. The simplicia was obtained by freeze drying to liquid preparation of heated fresh sea cucumber. The antibacterial activity test was performed using well diffusion method. There were no any antibacterial activity found in the two methanol extracts of sea cucumber.
 Keywords: antibacterial agent, Stichopus hermanii, Stichopus variegatus

Source apportionment of PM2.5 at two Seattle chemical speciation sites

ABSTRACT Positive Matrix Factorization analysis of PM2.5 chemical speciation data collected from 2015–2017 at Washington State Department of Ecology’s urban NCore (Beacon Hill) and near-road (10th and Weller) sites found similar PM2.5 sources at both sites. Identified factors were associated with gasoline exhaust, diesel exhaust, aged and fresh sea salt, crustal, nitrate-rich, sulfur-rich, unidentified urban, zinc-rich, residual fuel oil, and wood smoke. Factors associated with vehicle emissions were the highest contributing sources at both sites. Gasoline exhaust emissions comprised 26% and 21% of identified sources at Beacon Hill and 10th and Weller, respectively. Diesel exhaust emissions comprised 29% of identified sources at 10th and Weller but only 3% of identified sources at Beacon Hill. Correlation of the diesel exhaust factor with measured concentrations of black carbon and nitrogen oxides at 10th and Weller suggests a method to predict PM2.5 from diesel exhaust without a full chemical speciation analysis. While most PM2.5 sources exhibit minimal change over time, primary PM2.5 from gasoline emissions is increasing on average 0.18 µg m−3 per year in Seattle. Implications This study utilizes Positive Matrix Factorization to determine PM2.5 sources from chemical speciation measurements at two urban Seattle sites from 2015-2017. The paper reports PM2.5 source trends, and extends previous source apportionment analyses in Seattle to the present day. The study also quantifies diesel PM2.5 at a near-road site, and describes a predictive model that allows estimation of the contribution of diesel PM2.5 to the total measured PM2.5 at near-road sites across the country without a full chemical speciation analysis.

Lipid profile and health benefit of commonly consumed fresh water and sea water fish species in the population of Serbia

Background/Aim. Dietary intake of n-3 long-chain polyunsaturated fatty acids (LC-PUFA) is important in prevention and treatment of different diseases. In general population, the average intake of n-3 LC-PUFA is often significantly lower than recommended levels. Fish lipids are rich sources of these fatty acids, of which the most important are eicosapentaenoic (20:5 n-3, EPA) and docosahexaenoic (22:6 n-3, DHA) fatty acids. This study was designed to determine and compare fat, fatty acids and lipid quality indices in 10 commercial fish species available on the Serbian market, as well as relation between their price and nutritional value. Methods. Freshwater fish originated from the Danube River in the Belgrade Region, while seawater fish were mostly from the Adriatic Sea. A gas chromatography method was used to define fatty acids in 40 fish samples after lipid extraction. Cost-minimization analysis was conducted to assess the economic utility. Results. Seawater fish had a significantly higher value of flash lipid quality compared to the freshwater fish (p < 0.05). Value of hypercholesterolaemic fatty acids (OFA) for the freshwater group was 18.70 (17.40?21.30) while the seawater group had a similar range of values 18.90 (17.55?22.75). Hypocholesterolaemic fatty acids (DFA) also showed similar ranges for both groups: 68.80 (66?70.20) for freshwater and 68.40 (64.85?73.05) for seawater group. The ratio of DHA/EPA ranged from 1.8 for sardine samples and up to 10 for tuna samples, indicating that the amount of DHA in natural samples exceeds the amount of EPA in many cases. The values of atherogenic (AI) and thrombogenic index (TI) were lower than 1 for all analysed samples. Conclusion. Sardine and mackerel had the highest content of n-3 LC-PUFA and presented the least expensive sources of EPA and DHA. The low values of AI and TI obtained from studied fish indicate its benefits from a health point of view.

EKSPLORASI PROBIOTIK LOKAL UNTUK PERBAIKAN PEMBIBITAN DAN PEMBESARAN LELE SANGKURIANG


 ABSTRACT
 Catfish is one type of freshwater fish that is quite popular with the people of Indonesia. Catfish prices are relatively cheap, easily cultivated, and have high nutritional content. Efforts to improve the yield of catfish farming have been done in many different ways, one of which is probiotics. The purpose of giving probiotics is to improve water quality. The study was conducted from April to July 2019, in the Experimental Pool of the Faculty of Agriculture, University of Ratu Samban, Bengkulu Utara, Bengkulu Province. The study used a two-factor randomized block design. The first factor is the type of probiotics (J), consisting of 2 levels, namely: J1: types of sea fish, J2: types of fresh fish. The second factor is the dose of probiotics (P), consisting of 4 levels, namely: P1: dose of 1 ml of probiotics per 10 liters of water, P2: dose of 1.5 ml of probiotics per 10 liters of water, P3: dose of 2 ml of probiotics per 10 liters water, P4: dose of 2.5 ml of probiotics per 10 liters of water. The above treatment was repeated three times so that there were 24 experimental units. This study aims to obtain information about the exploration of local probiotics with the right dosage for nursery improvement and enlargement of sangkuriang catfish. The results showed that the utilization of probiotic types / sources originating from both fresh fish and sea fish turned out to have the same effect, but there was potential that the types / sources of probiotic fish produced higher absolute weight and absolute length. Probiotic doses have the same potential between low and high doses, but there is a tendency that 1.5 ml / 10 l water probiotic doses produce higher absolute length and absolute weight. There is no interaction between the types of probiotics and probiotic doses.
 
 Keywords: waste, fish, probiotics, catfish, sangkuriang

A Messinian model explains the salt contamination of the Mediterranean Coastal Springs

Mediterranean submarine karst springs could feed millions of persons in areas that suffer from scarcity of water but they are brackish which limits their use. The water comes from deep karst galleries which were explored by cave divers. There were many attempts to catch the water by building dams or bells to prevent sea intrusion in the cave, or to augment the water head for lowering the haline interface, according to the Ghyben–Herzberg relation. They failed as the water remained brackish upstream to the works. Recent studies show that salinity is acquired at a very important depth (> 200 m) by mixing of fresh water and sea water in deep zones where karst galleries were dug during the Messinian salinity crisis (5.9–5.3 Ma), when the sea level dropped down to 1500–2500 m. The validation of this Messinian model is a starting point for the use of this water resource by drilling deep wells, upstream of the galleries junction or by blocking the intrusion in the Messinian galleries.

Vehicle-induced fugitive particulate matter emissions in a city of arid desert climate

This study investigates and proposes emission factors (EFs) and models for vehicle-induced exhaust (VEX) and fugitive (VfPM) particulate matter emissions representative of areas with arid climates. Particle number (PNC) and mass (PMC) concentrations and their integrated samples were collected for a period of three months for both PM10 and PM2.5 next to a trafficked road in the city of Doha, Qatar. Using Positive Matrix Factorization (PMF) on the elemental data of the samples, six distinct PM sources were identified: traffic exhaust, dust resuspension, fresh and aged sea salt, secondary aerosols, and fuel oil/shipping. Dispersion modelling and regression analysis were combined to derive EFs (linear analysis) and models (non-linear analysis) for the total traffic fleet (heavy and light duty). The estimated EFs were between 620 and 730 mg VKT−1 (VKT; Vehicle Kilometer Travelled) (adj. R2 ~ 0.84) and between 1080 and 1410 mg VKT−1 (adj. R2 ~ 0.70) for VEX and VfPM, respectively. The integration of field measurements, chemical characterization, and dispersion modelling presented herein is one of the first similar studies conducted in the wider region, identifies the importance of fugitive PM (fPM), and marks the need for further studies to improve emissions modelling of VfPM in arid desert climates.

Synthesis and working mechanism of fluid loss additive by freeze-drying method

ABSTRACT A liquid fluid loss additive was synthesized by 2-acrylamide-2-methyl propane sulfonic acid (AMPS), N, N-dimethyl acrylamide (DMAM), maleic anhydride (MA), and allyl alcohol polyoxyethylene ether (APEG), which named ADMA (AMPS/DMAM/MA/APEG). The liquid ADMA was freeze-dried and grinded to a white powdery polymer (FDADMA). The FDADMA had less fluid loss volume and superior rheological properties both in fresh water and sea water, while ADMA merely exhibited good filtrate loss control and rheology in fresh water. Besides, the surface morphology of FDADMA was dendritic in sea water after freeze drying, while the ADMA was severely aggregated in sea water.