Small Pellets Research Articles

Application of different <i>k</i>-<i>ε</i> turbulence models on combustion process modelling in small-scale pellet stoves for household heating

Constant demand for development and construction improvement of small scale pellet stoves and boilers (nominal power up to 50 kWth) for household heating leads to conclusion that appropriate upgrading should be done on that field. Optimisation of stove construction should be performed based on results of experimental tests, as well as results of numerical analysis and mathematical modelling of combustion process. This is compulsory, because stove construction shall comply with demands for energy and environmental characteristics defined in appropriate quality standards. Besides, stove should operate with pellets of different quality, produced from various biomass raw materials. Considering that numerical analysis is less time consuming process than experimental tests, nowadays it is more often used for development and improvement of combustion appliance construction. As the turbulence modelling is one of the key parts in the eligible numerical analysis, the aim of the research presented in this paper is to define the influence of different k-ε turbulence models and their application on defined CFD mathematical model of combustion process in small-scale pellet stove for household heating.

Fuel Pellet Alignment in Heavy-Ion Inertial Fusion Reactor

In inertial confinement fusion, the scientific issues include the generation and transport of driver energy, the pellet design, the uniform target implosion physics, the realistic nuclear fusion reactor design, etc. In this paper, we present a pellet injection into a power reactor in heavy ion inertial fusion. We employ a magnetic correction method to reduce the pellet alignment error in heavy ion inertial fusion reactor chamber, including the gravity, the reactor gas drag force and the injection errors. We found that the magnetic correction device proposed in this paper is effective to construct a robust pellet injection system with a sufficiently small pellet alignment error.

Preparation of High Sphericity Li<sub>2</sub>TiO<sub>3</sub> Tritium Breeder by Polymer Assisted Sedimentation Method

The tritium breeder materials used in solid tritium breeding blanket of fusion reactor are lithium-based ceramics, like lithium titanate (Li2TiO3), lithium orthosilicate (Li4SiO4), lithium aluminate（LiA1O2) and lithium zirconate (Li8ZrO6). Among them, Li2TiO3 has the advantages of stable chemical property, high mechanical strength and high lithium content, so it has become one of the preferred materials. Based on the design of solid blanket and tritium extraction process, breeder materials need to be made into a certain shape of pebbles. B Spherical breeder is widely used in the design of fusion reactor for the larger specific surface area, more channels between the pebbles to diffuse and release tritium, and easier loading or unloading. However, due to the high requirements of the breeder pebbles, the production control are not complete. In this paper, a new preparation method of ceramic pellets with high sphericity, polymer assisted sedimentation method, was used to prepare ceramic pebbles. The slurry consists of micro-scaled ceramic powder and organic monomers. Spherical droplets of ceramic slurry were obtained by sedimentation method in viscous liquids. The organic monomer contained in the droplets was heated to polymerize into small pellet preforms during the sedimentation process. By optimizing the sintering process, the fabricated pebbles could perform high compressive load (>18 N), spherical shape (0.95~1.02), uniform particle size (0.8~1.2mm) and porosity (15~20 %). The main advantages of this method is the mild preparation conditions (50~110 °C), the simplified transfer and purification process and convenient industrialization.. The obtained product has high spherical shape, uniform particle size, high compactness and mechanical strength.

Ultrastructural and elemental characterization of the extracorporeal tube of the sessile rotifer Floscularia conifera (Rotifera: Gnesiotrocha)

Rotifers are aquatic microinvertebrates that live in the plankton or in the benthos, which may include a variety of macrophytes. Among these periphytic forms of rotifers, some have taken up a sessile existence and secrete protective tubes around their bodies. One type of tube common to species of Floscularia is made of small round pellets. To date, the building process and some fine structural details are known for Floscularia ringens, but many questions about the composition of the tube and its ultrastructure still remain unanswered. Here, we use transmission electron microscopy and scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM–EDS) to study the ultrastructure of the pellets and their elemental composition, respectively, in the putative sister species, Floscularia conifera. We revealed several new details that add important information about the physiology of tube-making in species of Floscularia. First, we note an inner secretory membrane that is thin, electron lucent, and supports the external pellets. The pellets are relatively consistent in size and have a small depression on their inner surface. All pellets are individually wrapped in a secretory membrane that completely encapsulates suspended materials collected from the surrounding water. Elemental signatures of pellets reveal they consist mostly of carbon (C), nitrogen (N), and oxygen (O), with some silicon (Si) content that is likely the result of diatom shells. Other trace elements such as iron (Fe) and sodium (Na) are also present and likely the result of incorporated bacteria and suspended materials. When larval rotifers are cultured in filtered pond water, the pellets consist mostly of C and O, with little N and no Si; Fe is present in smaller amounts. These new discoveries provide a better understanding of the physiology of rotifer tube construction and tube composition, and their future utility in understanding if and how changes in freshwater environments might impact these factors.

Effect of Food Predictability on Life Span in Male Mice.

The purpose of this study is to compare the effect of unpredictable (U) or predictable (P) food delivery on health and longevity in mice. From 2 months of age until end of life, singly-housed male C57BL/6 mice were fed a semisynthetic diet either ad libitum (AL), or as imposed meals delivered as small pellets at either P or U times, frequencies, or amounts. The total daily food consumed by all groups was the same. The AL group gained body weight faster than either P or U groups, and had ~12% shorter median life span compared with either P or U groups. Bimonthly noninvasive body composition determinations showed that the differences in body weights were due to differences in fat and lean mass. Postmortem examinations revealed that the organ pathologies were similar in all groups, but a larger fraction of P and U mice were euthanized due to end-of-life suffering. There were no systematic differences in outcome measures between P and U groups suggesting that, within the range studied, the temporal pattern of food delivery did not have a significant metabolic effect.

Review of strategies for MRI based reconstruction of endocavitary and interstitial applicators in brachytherapy of cervical cancer.

Brachytherapy plays an essential role in the curative intent management of locally advanced cervical cancer. The introduction of the magnetic resonance (MR) as a preferred image modality and the development of new type of applicators with interstitial components have further improved its benefits. The aim of this work is to review the current status of one important aspect in the cervix cancer brachytherapy procedure, namely catheter reconstruction. MR compatible intracavitary and interstitial applicators are described. Considerations about the use of MR imaging (MRI) regarding appropriate strategies for applicator reconstruction, technical requirements, MR sequences, patient preparation and applicator commissioning are included. It is recommendable to perform the reconstruction process in the same image study employed by the physician for contouring, that is, T2 weighted (T2W) sequences. Nevertheless, a clear identification of the source path inside the catheters and the applicators is a challenge when using exclusively T2W sequences. For the intracavitary component of the implant, sometimes the catheters may be filled with some substance that produces a high intensity signal on MRI. However, this strategy is not feasible for plastic tubes or titanium needles, which, moreover, induce magnetic susceptibility artifacts. In these situations, the use of applicator libraries available in the treatment planning system (TPS) is useful, since they not only include accurate geometrical models of the intracavitary applicators, but also recent developments have made possible the implementation of the interstitial component. Another strategy to improve the reconstruction process is based on the incorporation of MR markers, such as small pellets, to be used as anchor points. Many institutions employ computed tomography (CT) as a supporting image modality. The registration of CT and MR image sets should be carefully performed, and its uncertainty previously assessed. Besides, an important research work is being carried out regarding the use of ultrasound and electromagnetic tracking technologies.

Microstructural, thermochemistry and mechanical evaluation of self-reducing pellets using electric arc furnace (EAF) dust containing zinc for Waelz process

The increment of recycling of steel using electric arc furnace and the tendency to coat of steel products with zinc, in order to prevent corrosion, has increased the proportion of galvanized scrap used worldwide in the recent years. Approximately 10 to 20 Kg/t of cast steel is generated in casting arcs. These collected dusts electric arc furnace (EAF dust) contains iron, zinc, lead, and cadmium. Mainly in the form of oxides and their wastes are considered hazardous typically in countries such as Brazil, U.S., Japan and Germany. It is estimated that from the total of 7.5 million metric tons of EAF dust generated worldwide only 45% is recycled. With Waelz process, the EAF dust can be treated to recover zinc by means of reductionvolatilization- oxidation reactions occurring within the rotary kiln. In this work the thermodynamics of the Waelz process is studied to optimize the recovery of volatiles especially zinc. Kinetic parameters were evaluated trough series of ten experiments, comprise the major process factors such as type of reductants (charcoal and petroleum coke), time (20 – 120 minutes) and temperature (450 - 1150°C). The mechanical behavior of the pellets was evaluated by compressive cold strength and drop tests. Characterization was performed using scanning electron microscopy, microanalysis EDS, X-ray diffraction, X-ray fluorescence, granulometric analysis by laser diffraction, as well as measurements of moisture, bulk density and percentage of volatiles, fixed carbon and ash. The small pellets (10mm) with charcoal used as a reductant, presented a higher compression and higher recovery of volatiles than those with petroleum coke. Keywords: Self-reducing pellets; recovery of zinc; treatment of steelmaking waste; Waelz process.

Analyzing cleaner alternatives of solid and gaseous fuels for iron ore sintering in compacts machines

Abstract The steel industry has faced challenges with regard to the raw materials and fuels and hence economic and environmental restrictions. This paper is focused on searching alternatives based on biomass and gaseous fuels suitable for replacing the coke breeze fossil fuel. Nevertheless, testing these technologies are expensive. Therefore, comprehensive mathematical models based on transport phenomena are efficient tools to study and indicate new possibilities for designing operational conditions as well as resizing the machines for minimizing the hazardous emissions. We proposed new concept of operation combining gaseous fuels and biomass for partially replacing the coke breeze in a compact sintering machine. Thus three possible ways for 20% of the amount of coke breeze replacement are analyzed in a combined manner: a) replacement by steelmaking mixing gas, b) replacement by biogas and c) replacement by pellets of biomass. The results indicated that about 20% of the solid fossil fuels could be replaced by waste solid residue of biomass (processed as small pellets). For the analyzed cases, the productivity increase of 5% for the steelmaking mixing gas, 15% for the biomass pellets and 25% for the biogas fuel. For all cases considered it was predicted a decrease of the amount of hazardous compounds emissions.

Spatial instability and break-up of viscoelastic Giesekus curved jets with surfactants

This paper deals with the prilling process, which is widely used to produce small spherical pellets from molten material. To deliver pellets of a uniform size, it is essential to understand the mechanism of the break-up of liquid jets. In this paper, we propose a model of the viscoelastic liquid jet using the Giesekus constitutive equation and investigate drop formation of a viscoelastic curved liquid jet with a layer of surfactants along its free surface. Furthermore, the governing equations have been reduced to one dimension by using an asymptotic analysis. Then, the steady state solutions for a spiralling viscoelastic liquid jet with surfactants have been found, and therefore the spatial instability analysis has been performed to derive the eigenvalue relation. Moreover, the Lax–Wendroff method has been used to solve the nonlinear evolution equations for determining the break-up lengths and drop formation of viscoelastic Giesekus curved jets with surfactants.

Identification of the proto-inkstone by organic residue analysis: a case study from the Changle Cemetery in China

The inkstone is a specific writing implement in China that was popularized since the Han Dynasty (202 BC–AD 220). A rectangular/round grinding plate accompanied with a grinding stone is considered as a kind of proto-inkstone. However, little scientific investigation has been performed to support this hypothesis. In this paper, a micro-destructive approach, including Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and gas chromatography coupled with mass spectrometry (GC–MS), were employed to analyse the black residues on a grinding plate and a grinding stone excavated from the Changle Cemetery (202 BC–AD 8) in northwestern China. The FTIR and Raman analyses indicated that the residues were ancient ink. GC–MS analysis further identified that the residues were pine-soot ink, based on the relative abundances of the main polycyclic aromatic hydrocarbons, as well as the detection of conifer biomarkers. The trace of animal glue was not detected in the residues; thus, the ink was possibly formed as small pellets and the small grinding stone was necessary to assist during the ink-grinding process. This study confirms that this set of stone implements is indeed an early type of inkstone, and offers some insight into the co-evolution relationship between ink production and inkstone shapes.

Growth and mortality of coccolithophores during spring in a temperate Shelf Sea (Celtic Sea, April 2015)

Coccolithophores are key components of phytoplankton communities, exerting a critical impact on the global carbon cycle and the Earth’s climate through the production of coccoliths made of calcium carbonate (calcite) and bioactive gases. Microzooplankton grazing is an important mortality factor in coccolithophore blooms, however little is currently known regarding the mortality (or growth) rates within non-bloom populations. Measurements of coccolithophore calcite production (CP) and dilution experiments to determine microzooplankton (≤63 µm) grazing rates were made during a spring cruise (April 2015) at the Central Celtic Sea (CCS), shelf edge (CS2), and within an adjacent April bloom of the coccolithophore Emiliania huxleyi at station J2.CP at CCS ranged from 10.4 to 40.4 µmol C m−3 d−1 and peaked at the height of the spring phytoplankton bloom (peak chlorophyll-a concentrations ∼6 mg m−3). Cell normalised calcification rates declined from ∼1.7 to ∼0.2 pmol C cell−1 d−1, accompanied by a shift from a mixed coccolithophore species community to one dominated by the more lightly calcified species E. huxleyi and Calciopappus caudatus. At the CCS, coccolithophore abundance increased from 6 to 94 cells mL−1, with net growth rates ranging from 0.06 to 0.21 d−1 from the 4th to the 28th April. Estimates of intrinsic growth and grazing rates from dilution experiments, at the CCS ranged from 0.01 to 0.86 d−1 and from 0.01 to 1.32 d−1, respectively, which resulted in variable net growth rates during April. Microzooplankton grazers consumed 59 to >100% of daily calcite production at the CCS. Within the E. huxleyi bloom a maximum density of 1986 cells mL−1 was recorded, along with CP rates of 6000 µmol C m−3 d−1 and an intrinsic growth rate of 0.29 d−1, with ∼80% of daily calcite production being consumed.Our results show that microzooplankton can exert strong top-down control on both bloom and non-bloom coccolithophore populations, grazing over 60% of daily growth (and calcite production). The fate of consumed calcite is unclear, but may be lost either through dissolution in acidic food vacuoles, and subsequent release as CO2, or export to the seabed after incorporation into small faecal pellets. With such high microzooplankton-mediated mortality losses, the fate of grazed calcite is clearly a high priority research direction.

Reduction and melting separation mechanism of boron-bearing iron concentrate/coal composite pellet

Realizing the boron and iron separation through selective reduction and melting separation of boron-bearing iron concentrate is of great significance for the utilization of crude ludwigite. The reduction and melting separation mechanism of boron-bearing iron concentrate/coal composite pellet was systematically investigated. The reduction and melting separation test of small size pellet was performed to reveal the evolution of slag and iron in the melting separation process. The isothermal reduction experiment showed the relationship between reduction stage and melting separation stage, and the step reduction and melting separation was perfectly achieved. Coal particles existed through the reduction and melting separation process and finally formed brown residue around the separated product. The pellet could not realize melting separation when the B2O3 content in the concentrate was lower than 6.00 wt%.

NiMg/Ceria-Zirconia Cylindrical Pellet Catalysts for Tri-reforming of Surrogate Biogas

Cylindrical NiMg/Ce0.6Zr0.4O2 pellet catalysts with two different sizes (large, radius = 1.59 mm; small, radius = 0.75 mm) were produced by extrusion of powder catalysts. The small catalyst pellets had a higher specific surface area, pore volume, average pore size, radial crush strength, and resistance to breakage than the large pellets. Tri-reforming tests with surrogate biogas were conducted at 3 bar and 882 °C, with the feed molar ratios of CH4:CO2:air fixed at 1.0:0.7:0.95 and the H2O/CH4 molar feed ratio varied (0.35–1.16). The small catalyst pellets exhibited lower internal mass-transfer resistance and higher coking resistance compared to the large pellets. CO2 conversion decreased and H2/CO molar ratio increased with the increase of H2O/CH4 molar feed ratio, which are consistent with the trends predicted by thermodynamic equilibrium calculations. The results indicate that the NiMg/Ce0.6Zr0.4O2 catalyst pellets are promising for commercial scale applications.

Silver-Exchanged Mordenite for Capture of Water Vapor in Off-Gas Streams: A Study of Adsorption Kinetics

Reduced silver-exchanged mordenite (Ag0Z) has been recognized as the benchmark adsorbent for radioactive iodine removal from the nuclear fuel reprocessing off-gases. It has also been shown to have a considerable adsorption capacity for water vapor, which is a major component (tritiated water) in the off-gases of spent nuclear fuel reprocessing facilities. Therefore, understanding the kinetics of water vapor adsorption on Ag0Z is necessary for a better design of off-gas treatment systems. The adsorption kinetics were studied through adsorption experiments of water vapor on Ag0Z pellets and analyses of the kinetic data with adsorption models that describe processes of mass transfer and inter/intracrystalline diffusion. Uptake curves of water vapor on Ag0Z pellets were obtained with a continuous-flow adsorption system at temperatures of 25, 40, 60, 100, 150, and 200 °C and dew points from −53.6 °C to 12.1 °C. The diffusion-controlling factors were determined experimentally and analytically. It was found that the diffusion process of water vapor in Ag0Z pellets was controlled by macropore diffusion. Gas film mass-transfer resistance also contributed to the adsorption process of the 0.9 mm Ag0Z pellets, but it could be minimized with a high gas velocity and small pellet radius. Kinetic models including macropore diffusion (MD), linear driving force (LDF) and shrinking core (SC) were used to fit the uptake curves. The macropore diffusivity for water vapor adsorption on Ag0Z pellets was determined using the three models. It was found that the LDF and SC models could well describe the kinetic process, while the fitting with the MD model was not quite as good due to the existence of external mass-transfer resistance for the 0.9 mm Ag0Z pellets.

III ventriculostomia endoscópica no tratamento de hidrocefalia secundária à lesão penetrante do crânio por projétil de arma de fogo

Os autores relatam o caso de um paciente atingido por disparo de arma de fogo na região frontotemporal direita, que veio a desenvolver hidrocefalia aguda não-comunicante, secundária à obstrução da porção posterior do terceiro ventrículo por fragmentos metálicos, debris e coágulos. Após derivação ventricular externa e limpeza cirúrgica da lesão em caráter de emergência, o paciente foi submetido a a terceiro ventriculostomia endoscópica, com derivação interna do líquor (LCR) para as cisternas de base. Houve imediata resolução da sintomatologia de hipertensão intracraniana e a ressonância magnética pós-operatória, embora tenha demonstrado, ainda, persistência da ventriculomegalia, confirmou a abertura do assoalho do terceiro ventrículo e fluxo liquórico. Os autores não têm conhecimento, até a presente data, de caso semelhante relatado na literatura.

A Pilot Analysis of Morphometric Assessment of Itraconazole Brands Using Dermoscopy and its Relevance in the Current Scenario.

Background:Itraconazole (ITZ) is widely used for cutaneous and systemic mycoses. Its bioavailability is inconsistent and shows interindividual variations. The quality of ITZ pellets is an important factor determining its absorption profile and thereby the therapeutic effect. Analysis of morphometric characteristics is a surrogate method to determine the same. Pellet number and size are the most important parameters in this regard.Aim:We aimed to delineate few low-cost brands, the assessed variables of which fell within the formulated criteria.Materials and Methods:In all, 22 (100 mg) formulations of ITZ were included. The pellet number was calculated manually and pellet size was determined using a dermoscope with an inbuilt measurement tool. Furthermore, size variation with respect to the innovator US Food and Drug Administration (FDA)-approved brand was determined.Results:There is a large variation in pellet number and average pellet size among different brands. Pellet number ranged from 121 to 820 and average size from 959 to 1845 μm. Few brands had dummy pellets and loose powder within the capsule. Two brands within the price range of less than Rs. 20 per capsule fulfilled the three formulated criteria: of a good pellet count, small pellet size, and low size variation. Two other brands also satisfied these criteria but were priced between Rs. 20 and 30 per capsule. The innovator US FDA-approved brand had the highest number of pellets and minimum size variation but is the costliest of all assessed brands.Limitations of the Study:We cannot comment on inter-batch variation as ours was a one-point assessment. Advanced techniques such as scanning electron microscopy and drug release profile, which would have given further useful information on pellet quality, were beyond our scope.Conclusion:There is marked variation in the assessed characteristics of ITZ formulations. These morphometric characteristics may have a significant bearing on the quality of ITZ. And thus analysis of these can help clinicians make an informed decision in choosing an ITZ formulation to achieve optimal efficacy.

From Army service to physician to patient

From Army service to physician to patient William L. Freeman If my experience were a script for Clint Eastwood, the title would be, "The High-5, the Good, & the Bad." I have not experienced what some other vets unfortunately have, " . . . , & the Ugly." After graduating from college and my 2 ½ year stint in the Peace Corps in Colombia, and during the early U.S. buildup in Vietnam, I volunteered for the US Army and the Army's Special Forces ("Green Berets"), received intensive one year training as a Special Forces Independent Duty Medic to function as a physician where there was none, and was in Vietnam for two one-year tours. My four years of service did not result in any need for health care after discharge in December, 1968. My experiences as an Independent Duty Medic in Vietnam did, however, result in a strong desire to be a real physician. After completing the premed science requirements, I was accepted by the University of Washington (UW) School of Medicine, Seattle, in September 1970, and then UW Family Medicine Residency. Part of that Residency included two months on the Internal Medicine [End Page 90] Service of the Seattle VA Hospital that was affiliated with the UW. The Director of that Service, who was also the Attending Physician with whom we residents met every day, was one of the most humane Attending Physicians I had during my three year Residency. He taught and practiced not only medical science but also compassionate medical caring for the VA's patients. After residency in 1977, I entered the Public Health Service (PHS), specifically the Indian Health Service. PHS is a "Uniformed Service," and thus I was eligible to receive care at military and VA hospitals. Fast forward to 1998. That year I was found to have a slightly elevated PSA test—"Prostate-Specific Antigen," indicating possible prostate cancer—during episodic medical care for other reasons at the U.S. Naval Hospital in Bethesda while on temporary duty nearby. I went to the combined university + VA hospital near my permanent duty station in the Southwest. The faculty-doctor had a reassuring patient-doctor manner. The six prostate needle biopsies were done in late July by the Urology Chief Resident there—he had just started his year as Chief Resident. The results included one biopsy lost and the others inconclusive. I asked to be seen by the Prostate Cancer Program at the Walter Reed Army Medical Center, a program with a superb reputation. The doctor I saw there instilled confidence—and did 13 prostate biopsies with great skill. The biopsies were read by the Walter Reed pathologists; they disagreed among themselves on the interpretation and thus sent the biopsies to the next-door Armed Forces Institute of Pathology, the premier pathology institute whose readings were the gold standard in pathology. Final diagnosis: early prostate cancer. I had to decide which possible treatment to do: surgery (prostatectomy to remove the whole prostate); radiation therapy (kill the prostate and its cancer by radiation from outside the body); brachytherapy (insert several radioactive small pellets to kill the prostate and its cancer from the inside); or "watchful waiting" (follow PSA tests, to do an active treatment only if the PSA progressed higher). I, was 57 years old; my wife Carolyn and I decided against "watchful waiting." I visited a physician in charge of each type of active treatment. The first was the head of urological surgery at the same university + VA hospital in the Southwest. He maintained no eye contact with me, staring at my medical chart as he recited his information non-stop for me (i.e., what the prostatectomy would be, its recovery time, and why it would be the best treatment option for me). I did not go back. Instead, regarding the surgical option, I met with the urological surgeon at Walter Reed who had done my 13 biopsies; I then met with the doctor in charge of Radiation Therapy at Walter Reed. Both visits had a more gratifying doctor-patient interaction. A pioneer of brachytherapy treatment for prostate cancer and research about its results had recently moved from Memorial Sloan Kettering Cancer Center in New York City to...

Effect of Aerobic Exercise on Morphine Self-administration and Pain Modulation in Rats.

Background:Exercise reverses retention deficit induced by morphine. The present study investigated the effect of aerobic exercise on tolerance to morphine usage and pain modulation.Materials and Methods:Male Wistar rats were divided into four groups as follows: (1) saline group (S), (2) morphine group (M), (3) saline + exercise (S + E), and (4) morphine + exercise group (M + E). The rats were initially trained to receive small pellets of food by pressing an active lever in the self-administration apparatus. The tail-flick and hot-plate tests were used for pain assessment. To perform the experiment, the jugular vein was exposed and cannulated. After recovery, the animals were placed in the self-administration apparatus and allowed to self-administer morphine in 2 h sessions over 11 consecutive days.Results:The morphine group was found to record a higher number of active lever pressings than did the saline one while this parameter decreased in the morphine + exercise group compared with the morphine one. Moreover, the morphine + exercise exhibited lowered pain sensitivity as evidenced to have reduced morphine use in the hot plate test.Conclusion:The exercise might be suggested to reduce using of morphine and modulate pain probably through the release of endogenous opioid.

Thermo-capillary effect on the linear temporal and spatial instability of viscous liquid jets falling under gravity

Abstract The thermal modulation of Newtonian liquid jets at the orifice causes a variation in surface tension, which propagates downstream inducing Marangoni instability. Therefore, the linear temporal and spatial instability should be investigated to predict the same size of producing small spherical pellets. In this paper, we consider a viscous liquid jet emerging from a nozzle subject to thermo-capillary effects falling under gravity. Moreover, we use the asymptotic approach to reduce the governing equation into one-dimensional (1-D). The steady state solutions have been found using a modified Newton's method, and then the linear instability analysis has been investigated of the resulting set of equations.

Fertilizer value and greenhouse gas emissions from solid fraction pig slurry compost pellets

SUMMARYConversion of pig slurry to pellets is a desirable fertilizer option for farmers who want to mitigate environmental pollution from slurry accumulation. The goals of the current investigation were to determine the fertilizer properties of pig slurry solid fraction (SF) pellets and to assess its potential to enhance soil properties in order to reduce ammonia (NH3) volatilization and greenhouse gas (GHG) emissions. Various parameters influence SF-based pellet fertilizer effectiveness: bulking agent use during composting, pellet diameter sizing and soil application type (superficially or incorporated into the soil). Two composts from the same pig slurry SF obtained from a screw press separator were prepared: pig SF compost without a bulking agent (SSFC) and pig SF compost with wood chips as the bulking agent (wood chip compost (WCC)). For each compost type, pellets of two different diameters (6 and 8 mm) were produced. A mesocosm experiment, conducted with maize plants, was used to test the fertilizer value of the considered pellets. In total, three compost fertilizers – SSFC, WCC and nitrogen: phosphorus: potassium mineral fertilizer 15 : 15 : 15, plus one unfertilized control treatment – were applied at the same N rate (equivalent to 200 kg/ha) using two different methods (surface and soil incorporation). After 65 days, above-ground biomass, roots and soil samples were collected and analysed. Subsequently, a second mesocosm study was undertaken to measure NH3and GHG emissions released from pellet fertilization. Ammonia volatilization was determined immediately after pellet application, while carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) emissions were monitored for 57 days. Study results indicated that both pellet types were effective slow-release fertilizers for maize. Additionally, three actions seemed to make the nutrients contained in pig SF compost pellets more available to plants: addition of a bulking agent before composting, use of small diameter pellets and soil incorporation of the fertilizer.