bluuebunny/crossref_metadata_2025 huggingface dataset:
Ethics in animal breeding
Authors: Farstad Wenche
Published: November 2018

Contents

Ethical breeding involves the use of healthy animals true to their species in behaviour and physical appearance, and when applicable, showing a sustainable performance. The concerns for the species/breed are essential parts of the breeding goals, including preservation of genetic resources within the species/breed, and the health and welfare of the individual animal. Ethical and welfare considerations were often not prioritized in developing new breeds of production or companion animals. As a result, animal breeding practices are increasingly becoming part of the debate on animal welfare. In companion animals, breeding for curiosity or “cuteness” may be a goal in itself, although dogs are also bred for utility. In production animals, breeding focus is on performance, i.e., quantitative entities and financial income, rather than physical appearance. For instance, dairy cows are bred to be larger and to have higher milk yields, sows and ewes to produce more offspring, and horses are designed for riding, racing, and companionship. Overbreeding in relation to current demand of horses, cats, and dogs raises welfare issues due to abandonment or killing of horses and millions of cats and dogs every year. There is variable regulation of health requirements for breeding animals in different countries of the world. In many countries, consumers are becoming increasingly aware of animal welfare issues such as negative effects of certain production traits in farm animals, leading to decreased demand for their meat at a time where increased food production is becoming crucial. Amidst these dilemmas are the veterinarians. This paper deals with issues connected to traditional breeding as well as some of the breeding technologies, and includes food safety, ethics, and animal welfare.
Nuclear competence and genetic expression of growth differentiation factor‐9 (GDF‐9) of canine oocytes in 3D culture
Authors: Morselli Maria Giorgia , Loiacono Monica , Colombo Martina , Mortarino Michele , Luvoni Gaia Cecilia
Published: November 2018

To evaluate the ability of a 3D culture system in improving the nuclear and molecular competence of canine oocytes, barium alginate microcapsules were used for in vitro maturation (IVM) and the expression profile of one selected oocyte‐secreted factor, the growth differentiation factor‐9 (GDF‐9) was analysed. In Experiment I, canine grade I cumulus–oocyte complexes (COCs) were in vitro matured in 3D microcapsules in a controlled atmosphere for 72 hr, and meiosis resumption rates were compared to those of oocytes cultured in traditional 2D microdrops of medium. In Experiment II, a primer pair specific for canine GDF‐9 was designed, and preliminary tested in conventional PCR on genomic DNA. Total RNA content was isolated from oocytes at different time intervals (T0‐T24‐T48‐T72) during in vitro 3D culture, and a reverse transcription to cDNA was performed. The expression of target gene was assessed by quantitative Reverse Transcription Real‐Time PCR (qRT‐PCR), and the obtained amplicons were sequenced to check the specificity of the analysis. Canine COCs resumed meiosis at higher rates in 3D microcapsules than in 2D microdrops (p < 0.05), even though no significant differences in the proportions of oocytes achieving full maturational stages were obtained. A significant dynamic decrease in GDF‐9 expression was recorded during culture: after 72 hr of IVM, the GDF‐9 transcription significantly dropped (p = 0.018) compared to 24 and 48 hr. In conclusion, in vitro 3D culture represents an efficient system for IVM of canine oocytes, and the expression profile of GDF‐9 well reflects temporal dynamics for the acquisition of developmental competence in this species.
Accuracy of ultrasonography and fine‐needle aspiration cytology in the diagnosis of prostate diseases in dogs
Authors: Rodak Olga , Dzimira Stanisław , Podolak Aleksandra , Płóciennik Michał , Niżański Wojciech
Published: November 2018

Clinical signs of prostatic diseases in dogs are often non‐specific. Appropriate treatment should be based on a detailed investigation using reliable diagnostic tools. The aim of our study was to evaluate the diagnostic value of ultrasonography (US) and fine‐needle aspiration (FNA) cytology in dogs' prostate diseases. The mean accuracy of FNA cytology and US were 0.72 and 0.88 (n = 13), respectively. US gland size measurements and actual gland dimensions were highly concordant. Obtained results confirm the high diagnostic value of US and FNA biopsy and in prostatic diseases. Diagnosis based on US is highly reliable; however, it should be combined with clinical signs. Therefore, cytological evaluation of prostate gland material may be performed to differentiate or confirm presumptive diagnosis.
Gonadotropin‐releasing hormone‐modified chitosan as a safe and efficient gene delivery vector for spermatogonia cells
Authors: Boonthum Chatwalee , Namdee Katawut , Khongkow Mattaka , Temisak Sasithont , Chatdarong Kaywalee , Sajomsang Warayuth , Ponglowhapan Suppawiwat , Yata Teerapong
Published: November 2018

Contents

The use of male gonadal tissue as a site for the local delivery of DNA is an interesting concept. Previously, we reported synthesis, physiochemical and biological properties of gonadotropin‐releasing hormone (GnRH)‐conjugated chitosan as a carrier for DNA delivery to GnRH receptor‐overexpressing cells. In this study, the application of modified chitosan as a potential vector for gene delivery to testicular cells was carried out. Transfection efficiency was investigated in mouse‐derived spermatogonia cells (GC‐1 cells) using green fluorescent protein as a reporter gene. GnRH‐conjugated chitosan exhibited higher transfection activity and specificity compared to the unmodified chitosan. Furthermore, the GnRH‐modified chitosan showed less cytotoxicity. In conclusion, we have developed and successfully tested the GnRH‐modified chitosan for delivery of a transgene of interest to spermatogonia cells in vitro. Such vector could be useful in particular for testis‐mediated gene transfer.
Ultrasonographic evaluation of ovarian morphology and blood flow in prepubertal and pubertal cats
Authors: Vercellini Rosario , Gobello Cristina , D'Francisco Florencia , Olguín Silvia , Arizmendi Analía , Rodríguez Raúl , Arias Daniel Osvaldo , Blanco Paula G.
Published: November 2018

The aim of this study was to evaluate two‐dimensional and Doppler ultrasonographic changes of feline ovaries before and during puberty. Nine, 3‐month‐old female cats were followed until puberty (Day 1). Two‐dimensional and Doppler ultrasound evaluations of the ovaries were carried out on Days ‐50, ‐20, ‐7 and 1. Longitudinal and transverse sections of the ovaries were measured and all anechoic spherical structures were considered to be follicles. The number of follicles >1 mm and the maximum diameter of the largest follicle were recorded. Peak systolic velocity and end diastolic velocity of intraovarian arteries were also measured to automatically calculate the resistive index (RI). The mean ovarian longitudinal diameter increased gradually throughout the study from 8.6 to 10.7 mm (p < 0.05). While four cats presented multiple anechoic spherical structures <1 mm diameter throughout the study, the remaining five animals had these structures only on Days ‐50 and ‐20. On Days ‐20, ‐7 and 1, the mean number of follicles were 1.4 ± 0.7, 2.5 ± 0.8 and 4.8 ± 1 respectively (p < 0.01). The largest follicles at the same time points were 1.1 ± 0.2 mm, 1.9 ± 0.3 mm and 2.6 ± 0.5 mm respectively (p < 0.05). The RI of the intraovarian arteries declined throughout the study period (p < 0.01). It is concluded that, in female cats, ovarian dimensions, follicle number and intraovarian blood flow increased from 3 months of age to puberty.
Addiction to debt forgiveness in developing countries: Consequences and who gets picked?
Authors: Brown Leanora Alecia , Martinez‐Vazquez Jorge
Published: November 2018

We explore whether the expectation of debt forgiveness discourages developing countries from attaining sustainable fiscal independence through improving their tax effort. While the international financial community advises poor countries to improve revenue mobilization, the same international community routinely bails out poor countries that fail to meet their loan repayment obligations, among other reasons as a result of the low tax effort they exercise. The act of bailing out creates an expectation about receiving debt forgiveness time and again in the future. The key prediction of our theoretical framework is that in the presence of debt forgiveness, countries’ tax efforts will decline and more so the higher the intensity of the bailouts. We test this proposition using data for 55 countries from 1995 to 2015. We find that debt forgiveness is significant in lowering tax effort. In addressing the potential of reverse causality, we also find that the international financial community has been more forgiving to countries that exert lower tax effort. These results, which are robust to various specifications, have significant policy implications for donor and recipient countries.
Vintage Effects In Human Capital: Europe Versus The United States
Authors: Inklaar Robert , Papakonstantinou Marianna
Published: November 2018

The standard assumption in growth accounting is that an hour worked by a worker of given type delivers a constant quantity of labor services over time. This assumption may be violated due to vintage effects, which were shown to be important in the United States since the early 1980s, leading to an underestimation of the growth of labor input (Bowlus anA1d Robinson, 2012). We apply their method for identifying vintage effects to a comparison between the United States and six European countries. We find that vintage effects led to increases of labor services per hour worked by high‐skilled workers in the United States and United Kingdom and decreases in Continental European countries between 1995 and 2005. Rather than a productivity growth advantage of the US and UK, the primary difference with Continental European countries was human capital vintage effects instead.
Non‐failure blood flow restricted exercise induces similar muscle adaptations and less discomfort than failure protocols
Authors: Sieljacks Peter , Degn Rune , Hollaender Kasper , Wernbom Mathias , Vissing Kristian
Published: November 2018

Low‐load blood flow restricted resistance exercise (BFRE) performed to volitional failure is suggested to constitute an effective method for producing increases in muscle size and function. However, BFRE to failure may entail high levels of perceived exertion, discomfort, and/or delayed onset of muscle soreness (DOMS). The aim of the study was to compare BFRE performed to volitional failure (F‐BFRE) vs non‐failure BFRE (NF‐BFRE) on changes in muscle size, function and perceptual responses. Fourteen young untrained males had one leg randomized to knee extension F‐BFRE while the contralateral leg performed NF‐BFRE. The training consisted of 22 exercise bouts over an 8‐week period. Whole‐muscle cross‐sectional area (CSA) of quadriceps components, muscle function, and DOMS were assessed before and after the training period. Perceived exertion and discomfort were registered during each exercise bout. Both F‐BFRE and NF‐BFRE produced regional increases in muscle CSA in the range of: quadriceps (2.5%‐3.8%), vastus lateralis (8.1%‐8.5%), and rectus femoris (7.9%‐25.0%). All without differences between leg. Muscle strength (6.8%‐11.5%) and strength‐endurance capacity (13.9%‐18.6%) also increased to a similar degree in both legs. Less perceived exertion, discomfort, and DOMS were reported with NF‐BFRE compared to F‐BFRE. In conclusion, non‐failure BFRE enables increases in muscle size and muscle function, while involving reduced perceptions of exertion, discomfort, and DOMS. Non‐failure BFRE may be a more feasible approach in clinical settings.
If the Lord Is Willing and the Creek Don't Rise: Religious Attendance and Disaster Recovery in the Deep South*
Authors: Bright Candace Forbes , Hanks Roma , Sayre Edward , Broyles Amye , Bagley Braden
Published: November 2018

Objective

This article examines the association between religious attendance and disaster recovery in Mississippi and Alabama.

Methods

We use ordinary least squares regression to determine the effect of sociodemographic variables, social network size, and religious attendance on one's self‐described level of disaster recovery.

Results

We find a robust association between frequent religious attendance and a greater level of recovery. Somewhat surprisingly, we also find a strong relationship between religious nonattendance and a greater level of recovery. However, these results differ by race. For whites (but not for blacks), nonattendance is associated with a greater degree of recovery, while for blacks (but not for whites), frequent attendance is correlated with a greater degree of recovery. For both whites and blacks, the size of one's social network does not affect disaster recovery.

Conclusion

While according to previous research, religious attendance is associated with benefits based upon social networks and community engagement, we find that those who are strongly connected to their religious organizations recover more, but it is not directly connected to one's social network size.
Genetic variant in the NSDHL gene in a cat with multiple congenital lesions resembling inflammatory linear verrucous epidermal nevi
Authors: De Lucia Michela , Bauer Anina , Spycher Melina , Jagannathan Vidhya , Romano Erica , Welle Monika , Leeb Tosso
Published: November 2018

Background

The feline counterpart of human inflammatory linear verrucous epidermal nevus (ILVEN) has been described; however, the possible underlying developmental defect has not been investigated.

Objective

To report a case of multiple ILVEN‐like lesions in a cat with a genetic variant in the NSDHL gene.

Animals

A 2‐year‐old, female, domestic short hair cat with a history of multiple alopecic, verrucous, hyperpigmented and erythematous skin lesions, following Blaschko's lines on the head, the limbs, the trunk and paw pads.

Methods and results

According to the clinical and histopathological findings, a diagnosis of multiple ILVEN‐like lesions was made. Genetic investigation revealed a heterozygous missense variant in the X‐chromosomal NSDHL gene predicted to lead to a loss‐of‐function of the NSDHL protein.

Conclusions and clinical importance

To the best of the authors’ knowledge, this is the first case of feline ILVEN‐like lesions in which a genetic cause has been proposed. Future studies to establish a causal relationship between NSDHL variants and skin lesions might lead to pathogenesis‐directed treatments.
Dermatitis caused by autochthonous Cercopithifilaria bainae from a dog in Florida, USA: clinical, histological and parasitological diagnosis and treatment
Authors: Boyd Megan , Santoro Domenico , Craft William F. , Ginn Pamela E. , Childress April L. , Wellehan James F.X. , Walden Heather Stockdale
Published: November 2018

Background

Cercopithifilaria bainae is a tick‐vectored filarioid nematode associated with erythematous dermatitis in dogs. It has not been reported previously in the United States.

Hypothesis/Objective

To describe clinical, histological and parasitological diagnosis and treatment of C. bainae in a dog.

Animals

An 11‐month‐old golden retriever/standard poodle mixed breed dog from Florida (USA).

Methods and materials

The dog had no travel history within or outside the United States, was presented with a one month history of annular erythematous plaques on the head and ulcers on the medial canthi. Lesions were unresponsive to antibiotic treatment.

Results

Histopathological evaluation of skin biopsies revealed an eosinophilic to lymphohistiocytic perivascular dermatitis with multiple microgranulomas and rare 5–10 μm diameter microfilariae within microgranulomas. Microfilarial morphology was consistent with C. bainae. PCR and sequencing of 18S rRNA and mitochondrial cytochrome oxidase subunit I genes confirmed the nematodes as C. bainae. The dog was treated with a commercial spot‐on containing imidacloprid and moxidectin, and clinical resolution occurred.

Conclusions and clinical importance

To the best of the authors’ knowledge, this is the first report of C. bainae in a dog in the United States and the first description of dermatological lesions caused primarily by C. bainae.
Prevalence of CD20+ cutaneous epitheliotropic T‐cell lymphoma in dogs: a retrospective analysis of 24 cases (2011–2018) in the USA
Authors: Ewing Trenton S. , Pieper Jason B. , Stern Adam W.
Published: November 2018

Background

Limited information is known about the baseline frequency of canine CD20 positive (+) cutaneous epitheliotropic T‐cell lymphoma. A single canine case report has been published.

Objectives

To characterize the baseline frequency of CD20+ staining in cases of canine cutaneous epitheliotropic T‐cell lymphoma; to assess its values as a prognostic indicator.

Animals

Skin biopsies from 24 client‐owned animals diagnosed with cutaneous epitheliotropic lymphoma were assessed.

Methods and materials

A retrospective review of medical records from 2011 to 2018. Clinical histories and previous histological and immunohistochemical slides were collected from 24 dogs and additional immunohistochemical staining was performed as needed to assess cases of cutaneous epitheliotropic T‐cell lymphoma for CD3, CD20, CD79a and PAX5 staining characteristics. Staining characteristics were assessed for their statistical relationship to median survival time.

Results

Overall median survival time was 189 days following the onset of clinical signs and 99 days following definitive diagnosis; 54% of cases had CD20+ staining. There was no statistically significant correlation between staining characteristics and median survival time from onset of signs (P = 0.54) or from diagnosis (P = 0.61).

Conclusions and clinical significance

Canine cutaneous epitheliotropic lymphoma has a higher instance of CD20 positivity than documented previously. This indicates that CD20 staining may be unsuitable to differentiate T‐cell and B‐cell cutaneous epitheliotropic lymphoma. This also may have therapeutic implications with the advent of canine CD20 monoclonal antibody therapies.
Growth pattern of Juncus effusus and Juncus conglomeratus in response to cutting frequency
Authors: Kaczmarek‐Derda W , Østrem L , Myromslien M , Brandsæter L O , Netland J
Published: November 2018

Increasing abundance of Juncus effusus (soft rush) and Juncus conglomeratus (compact rush) in pastures and meadows in western Norway has caused reductions in forage yield and quality in recent decades. Understanding plant development and regrowth following cutting is essential in devising cost‐effective means to control rushes. In a field experiment in western Norway, we investigated development of above‐ and below‐ground fractions of rush from seedlings to three‐year‐old plants, including the impact on vigour of disturbing growth by different cutting frequencies during the period 2009–2012. Each year, the plants were exposed to one or two annual cuts or left untreated and five destructive samplings were performed from March to early December. Juncus effusus showed significantly more vigorous growth than Juncus conglomeratus in the last two years of the study period. The above‐ground:below‐ground biomass ratio of both species increased mainly in spring and early summer and was reduced in late summer and autumn. Removal of aerial shoots also reduced the below‐ground fraction of both species. One annual cut in July effectively reduced biomass production in both species by 30–82%, which was only a slightly smaller reduction than with two annual cuts, in June and August. Mechanical control measures such as cutting can thus effectively reduce rush vigour when performed late in the growing season.
Cattle‐associated risk factors for human tuberculosis in rural livestock‐keeping communities, Uganda
Authors: Meisner Julianne , Curtis Kellie , Graham Thomas W. , Apamaku Michael B. , Manhart Lisa E. , Rabinowitz Peter M.
Published: November 2018

Tuberculosis (TB) is a leading infectious cause of human death worldwide. In cattle, TB infection results in productivity losses, trade barriers and zoonotic transmission via milk, meat or direct contact. We conducted a cross‐sectional study in rural communities in Uganda between 2014 and 2016 to evaluate the association between tuberculosis skin test (TST) positivity in humans and cattle‐associated risk factors: household herd positivity and raw milk consumption. Human and cattle TSTs were performed in communities followed by a survey of household practices. TST data were available on 493 humans, 184 (37.3%) with positive results, and 1,441 cattle, 50 (3.5%) with positive results. We fit separate log binomial generalized estimating equation models for the herd positivity‐human TST positivity association, stratified on sex; and for the raw milk consumption‐human TST positivity association, stratified on frequency of milk consumption. Having at least one TST‐positive bovid in the household's herd was significantly associated with lower risk of TB among men (prevalence ratio [PR] 0.66, 95% CI 0.49, 0.87) but was not significantly associated with TB among women (PR 1.21, 95% CI 0.76, 1.95). This apparent protective effect was contrary to our a priori hypothesis of higher exposure effect among men, the primary caretakers of cattle. This finding may be the result of residual confounding by socioeconomic status; wealthier individuals may be less likely to be TB positive, but more likely to have TST‐positive herds by virtue of larger herd sizes, ability to purchase new and possibly infected stock, and propensity to keep more TB‐susceptible European breeds. For raw milk consumption, effect estimates were close to one and not statistically significant. Thus, in settings where bovine TB prevalence is low, such as Uganda, cattle‐associated zoonotic transmission may be rare, and cattle‐associated risk factors may not be important drivers of human TB burden.
Breeding Properties Study on High-Power Thorium Molten Salt Reactor
Authors: Liu Yafen , Guo Rui , Cai Xiangzhou , Yan Rui , Zou Yang , Zhou Bo
Published: November 2018

Molten salt reactor (MSR), the only one using liquid fuel in the six types “Generation IV” reactors, is very different from reactors in operation now and has initiated very extensive interests all over the world. This paper is primarily aimed at investigating the breeding characteristics of high-power thorium molten salt reactor (TMSR) based on the two-fluid molten salt breeder reactor (MSBR) with a superior breeding performance. We explored the optimized structure to be a thorium-based molten salt breeder reactor with different core conditions and different postprocessing programs, and finally got the breeding ratio of 1.065 in our TMSR model. At last we analyzed the transient security of our optimized model with results show that the temperature coefficient of core is −3 pcm/K and a 2000 pcm reactivity insertion can be successfully absorbed by the core if the insertion time is more than or equal to 5 s and the core behaves safely.
Coupling of a Reactor Analysis Code and a Lower Head Thermal Analysis Solver
Authors: Madokoro Hiroshi , Miassoedov Alexei , Schulenberg Thomas
Published: November 2018

Due to the recent high interest on in-vessel melt retention (IVR), development of detailed thermal and structural analysis tool, which can be used in a core-melt severe accident, is inevitable. Although RELAP/SCDAPSIM is a reactor analysis code, originally developed for U.S. NRC, which is still widely used for severe accident analysis, the modeling of the lower head is rather simple, considering only a homogeneous pool. PECM/S, a thermal structural analysis solver for the reactor pressure vessel (RPV) lower head, has a capability of predicting molten pool heat transfer as well as detailed mechanical behavior including creep, plasticity, and material damage. The boundary condition, however, needs to be given manually and thus the application of the stand-alone PECM/S to reactor analyses is limited. By coupling these codes, the strength of both codes can be fully utilized. Coupled analysis is realized through a message passing interface, OpenMPI. The validation simulations have been performed using LIVE test series and the calculation results are compared not only with the measured values but also with the results of stand-alone RELAP/SCDAPSIM simulations.
Uncertain Structural Free Vibration Analysis With Non-Probabilistic Spatially Varying Parameters
Authors: Feng Jinwen , Li Qingya , Sofi Alba , Li Guoyin , Wu Di , Gao Wei
Published: November 2018

The uncertain free vibration analysis of engineering structures with the consideration of nonstochastic spatially dependent uncertain parameters is investigated. A recently proposed concept of interval field is implemented to model the intrinsic spatial dependency of the uncertain-but-bounded system parameters. By employing the appropriate discretization scheme, evaluations of natural frequencies for engineering structures involving interval fields can be executed within the framework of the finite element method. Furthermore, a robust, yet efficient, computational strategy is proposed such that the extreme bounds of natural frequencies of the structure involving interval fields can be rigorously captured by performing two independent eigen-analyses. Within the proposed computational analysis framework, the traditional interval arithmetic is not employed so that the undesirable effect of the interval overestimation can be completely eliminated. Consequently, both sharpness and physical feasibility of the results can be guaranteed to a certain extent for any discretized interval field. The plausibility of the adopted interval field model, as well as the feasibility of the proposed computational scheme, is clearly demonstrated by investigating both academic-sized and practically motivated engineering structures.
Acoustic Signatures of Left Ventricular Assist Device Thrombosis
Authors: Patel Priyesh , Mainsah Boyla , Milano Carmelo A. , Nowacek Douglas P. , Collins Leslie , Karra Ravi
Published: November 2018

Left ventricular assist devices (LVADs) are life-saving, surgically implanted mechanical heart pumps used to treat patients with advanced heart failure (HF). While life-saving, LVAD support is associated with a high incidence of complications, making early recognition and management of LVAD complications a critical need. Blood clot formation within the LVAD, known as LVAD thrombosis, is a catastrophic complication of LVAD therapy that often requires LVAD exchange due to delayed diagnosis and treatment. Using digital stethoscopes, we identified differences in acoustic spectra from two patients presenting with LVAD thrombosis compared with normally functioning LVAD pumps within the same patient. Importantly, these acoustic changes were present even in the absence of typical signs of HF that are often present in LVAD thrombosis patients. Our work suggests that acoustic spectral analysis of digital stethoscope signals could be used for early detection and mitigation of LVAD complications.
Detailed Flow and Heat Transfer Analyses in a Rib-Roughened Trailing-Edge Cooling Cavity With Impingement
Authors: Xue Fei , Taslim Mohammad E.
Published: November 2018

A rig, simulating two adjacent cooling cavities on the trailing side of an airfoil, made up of two trapezoidal channels is tested. Eleven crossover holes on the partition wall between the two channels create the jets. Two exit flow arrangements are investigated—(a) jets, after interaction with the target surface, are turned toward the target channel exit axially and (b) jets exit from a row of racetrack-shaped slots along the target channel. Flow measurements are reported for individual holes and heat transfer coefficients on the eleven target walls downstream the jets are measured using liquid crystals under steady-state conditions. Smooth as well as ribbed target surfaces with four rib angles are tested. Correlations are developed for mass flow rate through each crossover hole, varying the number of crossover holes. Heat transfer coefficient variations along the target channel are reported for a range of 5000–50,000 local jet Reynolds numbers. Major conclusions are: (1) Correlations are developed to successfully predict the air flow rate through each crossover hole for partition walls with six to eleven crossover holes, based on the pressure drop across the holes, (2) impingement heat transfer coefficient correlates well with local jet Reynolds number for both exit flow arrangements, and (3) case of target channel flow exiting from the channel end, at higher jet Reynolds numbers, produce higher heat transfer coefficients than those in the case of flow exiting through a row of slots along the target channel opposite to the crossover holes.
Experimental and Numerical Analysis of Additively Manufactured Coupons With Parallel Channels and Inline Wall Jets
Authors: Parbat Sarwesh Narayan , Yang Li , Min Zheng , Chyu Minking K.
Published: November 2018

Present paper developed a series of additively manufactured parallel cooling channels with streamwise wall jets inside, which could be suitable for double-wall and near-wall cooling configurations in gas turbine hot section components. The tested coupons consisted of parallel channels, each channel further divided into small chambers using several spanwise separation walls. Height of these walls was kept less than channel height, thus forming a slot with one of the end walls. Coolant entered from one side of channel and formed streamwise wall jet while crossing through the slot over to the downstream chamber. The test coupons were additively manufactured by selective laser sintering (SLS) technique using Inconel 718 alloy. Steady-state heat transfer experiments with constant wall temperature boundary condition were performed to analyze effect of pitch between subsequent slots and blockage ratio (ratio of separation wall height to channel height) on heat transfer. The channel Reynolds number ranged from 1800 to 5000. Numerical simulations were performed using ANSYS cfx solver with SST k–ω turbulence model to obtain detailed understanding of existing flow field. Experimental results showed heat transfer enhancement of up to 6.5 times that of a smooth channel for the highest blockage ratio of 0.75. Numerical results revealed complex flow field which consisted of wall jets along with impingement, separation, and recirculation zones in each chamber. For all configurations, gain in heat transfer was accompanied with high pressure drops. However, coupled with the high heat transfer, this design could lead to potential coolant savings.
Generating Contextual Design for Environment Principles in Sustainable Manufacturing Using Visual Analytics
Authors: Ramanujan Devarajan , Bernstein William Z. , Totorikaguena Maria Aurrekoetxea , Ilvig Charlotte Frølund , Ørskov Klaus Bonde
Published: November 2018

Design for environment (DfE) principles are helpful for integrating manufacturing-specific environmental sustainability considerations into product and process design. However, such principles are often overly general, static, and disconnected from production contexts. This paper proposes a visual analytics (VA)-based framework for generating DfE principles that are contextualized to specific production setups. These principles are generated through interactive visual exploration of design and process parameters as well as manufacturing process performance metrics corresponding to the production setup. We also develop a formal schema for aiding storage, updating, and reuse of the generated DfE principles. In this schema, each DfE principle is associated with corresponding product lifecycle data and the evidence that led to the generation of that principle. We demonstrate the proposed VA framework using data from an industry-led experiment that compared dry ice (DI)-based and oil-based milling for a specific production setup.
Fractional Order Version of the Hamilton–Jacobi–Bellman Equation
Authors: Razminia Abolhassan , Asadizadehshiraz Mehdi , Torres Delfim F. M.
Published: November 2018

We consider an extension of the well-known Hamilton–Jacobi–Bellman (HJB) equation for fractional order dynamical systems in which a generalized performance index is considered for the related optimal control problem. Owing to the nonlocality of the fractional order operators, the classical HJB equation, in the usual form, does not hold true for fractional problems. Effectiveness of the proposed technique is illustrated through a numerical example.
Critical Review of Stabilized Nanoparticle Transport in Porous Media
Authors: Meng Xiaoyan , Yang Daoyong
Published: November 2018

Over the past few decades, due to the special features (i.e., easily produced, large-surface-area-to-volume ratio, and engineered particles with designed surface properties), nanoparticles have not only attracted great attentions from the oil and gas industry but also had various applications from drilling and completion, reservoir characterization, to enhanced oil recovery (EOR). As sensors or EOR agents, thus, fate and behavior of nanoparticles in porous media are essential and need to be investigated thoroughly. Nevertheless, most of the published review papers focus on particle transport in saturated porous media, and all of them are about steady-state flow conditions. So far, no attempts have been extended to systematically review current knowledge about nanoparticle transport in porous media with single-phase and two-phase flow systems under both steady-state and unsteady-state conditions. Accordingly, this review will discuss nanoparticle transport phenomena in porous media with its focus on the filtration mechanisms, the underlying interaction forces, and factors dominating nanoparticle transport behavior in porous media. Finally, mathematical models used to describe nanoparticle transport in porous media for both single-phase flow and two-phase flow under steady-state and transient flow conditions will be summarized, respectively.
A New Photovoltaic Arrays Fixed Reconfiguration Method for Reducing Effects of One- and Two-Sided Mutual Shading
Authors: Horoufiany Majid , Ghandhari Reza
Published: November 2018

Low distance between photovoltaic (PV) arrays can lead to the mutual shading between them. This can lead to significant power losses. Usually, these shadows can be seen in PV plants with limited land such as buildings' roof. In this paper, a PV arrays fixed reconfiguration method is presented in order to reduce the effects of one- and two-sided mutual shadings in total cross tied (TCT) arrangements. Two-sided mutual shading appears when the array is shaded in two separate areas, while there is only one shaded part in the array in one-sided mutual shading. In this method, the physical locations of the modules are rearranged without changing the electrical interconnections. To reduce the effects of these shadings, first, their important features are explained. Then, the optimal array rearrangement is determined by considering all possible mutual shadows (MSHs). In mutual shading conditions, the obtained arrangement is capable of equally dispersing shaded modules in different array rows, while there is no need to add any additional switches or sensors. Due to this equal dispersion, there is no need to use the bypass diodes for maximum power extraction in this condition. The simulation results validate the effectiveness of this method.
Design, Construction, and Analysis of a Passive Indirect Solar Dryer With Chimney
Authors: Tedesco Felipe Cichetto , Bühler Alexandre José , Wortmann Sérgio
Published: November 2018

The growing demand for alternative technologies, of clean and sustainable nature, has fostered the development and improvement of equipment that uses solar energy for the dehydration of seeds and fruits. Such equipment has been used worldwide for hundreds of years; however, it remains uncommon in Serra Gaúcha, a region of great production of grapes and apples for natura consumption in the state of Rio Grande do Sul—Brazil. In order to investigate the economic and technical viability of solar dryers in the Serra Gaúcha, this work has as target the design, simulation, construction, and experimental analysis of an Indirect Passive Solar Dryer with Chimney. The prototype, divided into three parts: solar collector, dehydration chamber, and chimney, was built prioritizing materials of low cost, but that did not compromise its performance. The device was submitted to experiments, which observed: solar collector behavior very close to the simulated one; obtaining a coefficient of performance of 87% in the equipment; satisfactory rise in temperature at the collector outlet comparing to its inlet; and dehydration of apples with a reduction of 89% in mass with 32.78 MJ of energy delivered to the system. The prototype payback period was estimated in two years.
Modeling and Control of a Diesel Engine With Regenerative Hydraulic-Assisted Turbocharger
Authors: Zeng Tao , Zhu Guoming
Published: November 2018

Diesel engines are of great challenges due to stringent emission and fuel economy requirements. Compared with the conventional turbocharger system, regenerative assisted system provides additional degrees-of-freedom for turbocharger speed control. Hence, it significantly improves control capability for exhaust-gas-recirculation (EGR) and boost pressure. This paper focuses on modeling and control of a diesel engine air-path system equipped with an EGR subsystem and a variable geometry turbocharger (VGT) coupled with a regenerative hydraulic-assisted turbocharger (RHAT). The challenges lie in the inherent coupling among EGR, turbocharger performance, and high nonlinearity of the engine air-path system. A control-oriented nonlinear RHAT system model is developed; and a linear quadratic (LQ) control design approach is proposed in this paper to regulate the EGR mass flow rate and boost pressure simultaneously and the resulting closed-loop system performance can be tuned by properly selecting the LQ control weighting matrices. Multiple LQ controllers with integral action are designed based on the linearized system models over a gridded engine operational map and the final gain-scheduling controller for a given engine operational condition is obtained by interpreting the neighboring LQ controllers. The gain-scheduling LQ controllers for both traditional VGT-EGR and VGT-EGR-RHAT systems are compared with the in-house baseline controller, consisting of two single-input and single-output (SISO) controllers, against the nonlinear plant. The simulation results show that the designed multi-input and multi-output LQ gain-scheduling controller is able to manage the performance trade-offs between EGR mass flow and boost pressure tracking. With the additional assisted and regenerative power available on the turbocharger shaft for the RHAT system, engine transient boost pressure performance can be significantly improved without compromising the EGR tracking performance, compared with the baseline control.
Electrohydrodynamic Printing for Advanced Micro/Nanomanufacturing: Current Progresses, Opportunities, and Challenges
Authors: Han Yiwei , Dong Jingyan
Published: November 2018

The paper provides an overview of high-resolution electrohydrodynamic (EHD) printing processes for general applications in high-precision micro/nanoscale fabrication and manufacturing. Compared with other printing approaches, EHD printing offers many unique advantages and opportunities in the printing resolution, tunable printing modes, and wide material applicability, which has been successfully applied in numerous applications that include additive manufacturing, printed electronics, biomedical sensors and devices, and optical and photonic devices. In this review, the EHDs-based printing mechanism and the resulting printing modes are described, from which various EHD printing processes were developed. The material applicability and ink printability are discussed to establish the critical factors of the printable inks in EHD printing. A number of EHD printing processes and printing systems that are suitable for micro/nanomanufacturing applications are described in this paper. The recent progresses, opportunities, and challenges of EHD printing are reviewed for a range of potential application areas.
Mesh Sensitivity Analysis for Quantitative Shear Stress Assessment in Blood Pumps Using Computational Fluid Dynamics
Authors: Gross-Hardt Sascha , Boehning Fiete , Steinseifer Ulrich , Schmitz-Rode Thomas , Kaufmann Tim A. S.
Published: November 2018

The reduction of excessive, nonphysiologic shear stresses leading to blood trauma can be the key to overcome many of the associated complications in blood recirculating devices. In that regard, computational fluid dynamics (CFD) are gaining in importance for the hydraulic and hemocompatibility assessment. Still, direct hemolysis assessments with CFD remain inaccurate and limited to qualitative comparisons rather than quantitative predictions. An underestimated quantity for improved blood damage prediction accuracy is the influence of near-wall mesh resolution on shear stress quantification in regions of complex flows. This study investigated the necessary mesh refinement to quantify shear stress for two selected, meshing sensitive hotspots within a rotary centrifugal blood pump (the blade leading edge and tip clearance gap). The shear stress in these regions is elevated due to presence of stagnation points and the flow around a sharp edge. The nondimensional mesh characteristic number y+, which is known in the context of turbulence modeling, underestimated the maximum wall shear stress by 60% on average with the recommended value of 1, but was found to be exact below 0.1. To evaluate the meshing related error on the numerical hemolysis prediction, three-dimensional simulations of a generic centrifugal pump were performed with mesh sizes from 3 × 106 to 30 × 106 elements. The respective hemolysis was calculated using an Eulerian scalar transport model. Mesh insensitivity was found below a maximum y+ of 0.2 necessitating 18 × 106 mesh elements. A meshing related error of up to 25% was found for the coarser meshes. Further investigations need to address: (1) the transferability to other geometries and (2) potential adaptions on blood damage estimation models to allow better quantitative predictions.
On the Use of Symmetries in Building Surrogate Models
Authors: Giselle Fernández-Godino M. , Balachandar S. , Haftka Raphael T.
Published: November 2018

When simulations are expensive and multiple realizations are necessary, as is the case in uncertainty propagation, statistical inference, and optimization, surrogate models can achieve accurate predictions at low computational cost. In this paper, we explore options for improving the accuracy of a surrogate if the modeled phenomenon presents symmetries. These symmetries allow us to obtain free information and, therefore, the possibility of more accurate predictions. We present an analytical example along with a physical example that has parametric symmetries. Although imposing parametric symmetries in surrogate models seems to be a trivial matter, there is not a single way to do it and, furthermore, the achieved accuracy might vary. We present four different ways of using symmetry in surrogate models. Three of them are straightforward, but the fourth is original and based on an optimization of the subset of points used. The performance of the options was compared with 100 random designs of experiments (DoEs) where symmetries were not imposed. We found that each of the options to include symmetries performed the best in one or more of the studied cases and, in all cases, the errors obtained imposing symmetries were substantially smaller than the worst cases among the 100. We explore the options for using symmetries in two surrogates that present different challenges and opportunities: Kriging and linear regression. Kriging is often used as a black box; therefore, we consider approaches to include the symmetries without changes in the main code. On the other hand, since linear regression is often built by the user; owing to its simplicity, we consider also approaches that modify the linear regression basis functions to impose the symmetries.
Comparing the Effects of Design Interventions on the Quality of Design Concepts as a Reflection of Ideation Flexibility
Authors: Henderson Daniel , Jablokow Kathryn , Daly Shanna , McKilligan Seda , Silk Eli , Bracken Jennifer
Published: November 2018

Many tools, techniques, and other interventions have been developed to support idea generation within the design process. In previous research, we explored the separate effects of three such design interventions: teaming, problem framing, and design heuristics. In the teaming intervention, participants discussed a design prompt together but recorded their own ideas separately. In problem framing, multiple versions (framings) of each design prompt were used to elicit different solutions. In design heuristics, participants used specially designed cards to prompt new ways of thinking about the given design problem. In the current work, we compared the effects of these three interventions on students' design ideas with respect to one idea attribute in particular—quality. In total, 1088 design concepts were collected from 171 undergraduate students in engineering and industrial design from two universities. Individual cognitive style was also assessed using Kirton's Adaption–Innovation inventory (KAI). Six metrics taken from the design literature were used to assess the quality of each concept, namely: acceptability, applicability, clarity, effectiveness, implementability, and implicational explicitness. Paired t-tests and Pearson correlations were used to assess differences in quality between concepts generated with and without the three interventions; in addition, secondary effects were sought based on the cognitive styles and academic standings of the participants. Statistically significant differences were observed in design concept quality for the teaming and design heuristics interventions over the full sample and for some subgroups separated by cognitive style and academic standing. These results have implications for how educators teach design interventions and how students choose and apply interventions to affect the quality of their own design solutions.
Finite Element Method Simulations to Study Factors Affecting Buried Pipeline Subjected to Debris Flow
Authors: Ying Wu , Sixi Zha , Pengwei Jin
Published: November 2018

As the debris flow caused by sustained rainfall would cause destructive damage to buried pipeline, the safety of buried pipeline under impact of debris flow draws increasing attention. This paper focuses on the mechanical and deformed behavior of buried pipeline subjected to the debris flow. The effects of relevant parameters are investigated, including the velocity and impact angle of debris flow, massive stone, diameter to thickness ratio of pipeline (D/T), and parameters of corrosion pit (i.e., the depth, length, and width of corrosion pit). A finite model of soil and buried pipeline under the impact of debris flow is established. Multiple regression analysis is implemented to evaluate these influence parameters. The results show that: (1) the velocity and the impact angle of debris flow have a great influence on the pipeline; (2) the massive stone in the debris flow has little effect on the buried pipeline; (3) the internal pressure of the pipeline has an inhibitory effect on the deformation of the pipeline, which can enhance the ultimate bearing velocity of pipeline; (4) D/T determines the ultimate bearing velocity of pipeline. Moreover, the effects of the parameters of corrosion pit on the maximum von Mises stress are analyzed by multiple regression and ranked as follows: corrosion depth (A) > corrosion length (L) > corrosion width (B). The result may provide effective guidance for the prevention of pipeline against debris flow in mountain area.