Varying Energy Density Research Articles

In vitro digestion of oil-in-water emulsions stabilized by whey protein nanofibrils

The effect of pH (3 and 7) and varied energy density of a high-pressure homogenization process on the stability of oil-in-water (O/W) emulsions stabilized by whey protein fibrils was evaluated. A dynamic digestion model comprising the simulation of stomach, duodenum, jejunum and ileum, has been used to evaluate O/W emulsions' behavior under gastrointestinal (GI) conditions. The emulsions did not separate phases during the storage period (7 days). The emulsions stabilized by whey protein fibrils were stable under simulated gastric conditions but were destabilized in the simulated intestinal conditions. In a similar way, the whey protein fibrils' dispersion showed a high resistance to proteolytic in vitro digestion by pepsin (gastric stage) but was more readily degraded by pancreatin (intestinal stage). This fact confirms the significant impact of the interfacial characteristics on emulsions' digestion. The percentage of free fatty acids (FFA) absorbed in the simulated intestinal conditions (jejunum and ileum) was much lower than the total percentage of FFA released due to the use of WPI fibrils as emulsifier. This work contributes to a better understanding about the behavior of O/W emulsions stabilized by whey protein fibrils within the GI tract; this knowledge is fundamental when considering the final application of this protein in food products.

Antimicrobial effect of pleomeleangustifolia pheophytin A activation with diode laser to streptococcus mutans

The main purpose of this research is to identify potential of Pheophytin A. as photosensitizer a agent to inactivate Streptococcus muttans using laser diode of 405nm. Pheophytina is known as chlorophyll derivate that losses magnesium ion at the center of porphyrin ring structure. In this research, phrophytin was extracted from Suji leaf (Pleomeleangustifolia). To determine the antimicrobial effect of treatments on S. mutans, samples were divided into three groups as follows: (1) Groups A(treated with Pheophytin A. and laser 405 nm at varying energy density of 2.5; 5, 7.5; 10.0; 12.5; 15.0; 17.5 and 20.0 J/cm2), (2) Group C-(negative control, no treated), (3) Group C+ (treated only with pheophytin). The experiments were repeated at least three times for each group. The results were analyzed using analysis of variance and the Tukey test. A P value ≤0.05 was considered to indicate a statistically significant difference. The decrement of percentage of number of bacterial colonyes growth was defined as: | (Σ sample colony - Σ control colony)/ Σ control colony | x 100%. The result showed that the incubation of Pheophytin A. using irradiation from laser diode of 405nm have a significant effect towards the decrement in bacterial growth. The most decreased percentage colony of S. mutans occurred on the incubation of pheophytin a treatment and laser irradiation 405nm with density 20 J/cm2 is 61.9%. This showed that pheophytin a functions as a photosesitizer activator to inactivate S. mutans bacteria.

Structural evolution of tungsten surface exposed to sequential low-energy helium ion irradiation and transient heat loading

Structural damage due to high flux particle irradiation can result in significant changes to the thermal strength of the plasma facing component surface (PFC) during off-normal events in a tokamak. Low-energy He+ ion irradiation of tungsten (W), which is currently the leading candidate material for future PFCs, can result in the development of a fiber form nanostructure, known as “fuzz”. In the current study, mirror-finished W foils were exposed to 100eV He+ ion irradiation at a fluence of 2.6 ×1024ionsm−2 and a temperature of 1200K. Then, samples were exposed to two different types of pulsed heat loading meant to replicate type-I edge-localized mode (ELM) heating at varying energy densities and base temperatures. Millisecond (ms) laser exposure done at 1200K revealed a reduction in fuzz density with increasing energy density due to the conglomeration and local melting of W fibers. At higher energy densities (∼ 1.5MJm−2), RT exposures resulted in surface cracking, while 1200K exposures resulted in surface roughening, demonstrating the role of base temperature on the crack formation in W. Electron beam heating presented similar trends in surface morphology evolution; a higher penetration depth led to reduced melt motion and plasticity. In situ mass loss measurements obtained via a quartz crystal microbalance (QCM) found an exponential increase in particle emission for RT exposures, while the prevalence of melting from 1200K exposures yielded no observable trend.

Effects of laser-induced oxidation on the corrosion resistance of AISI 304 stainless steel

The paper presents an analysis of the impact of oxide layers, manufactured by means of laser radiation (with varying energy densities), on the resistance of AISI 304 stainless steel to corrosion. Corrosion resistance tests have been carried out in a weakly acidic environment (H2SO4, pH = 3.5) and a neutral environment (NaCl, pH = 7). The experiment was performed with the use of a laser system equipped with the Ytterbium Yb3+ fiber laser with a pulse duration of 230 ns. It has been shown that the thermal-oriented laser process significantly affects the course and nature of cathode-anode processes occurring on the surface of irradiated materials. Compared to the unstructured reference samples, there has been a significant increase in corrosion resistance of AISI 304 steel in the range of laser fluence between 50 and 70 J/cm2. The Energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy analyses of the chemical composition of the surface of the samples as well as the change of their morphology (microcracks of oxide layers) are closely correlated with the electrochemical measurements. Corrosion intensity has also been specified as a function of the energy density used for the laser marking of the samples.

Thermodynamic analysis of universes with the initial and final de Sitter eras

Our aim is studying the thermodynamics of cosmological models including initial and final de Sitter eras. For this propose, bearing Cai–Kim temperature in mind, we investigate the thermodynamic properties of a dark energy (DE) candidate with variable energy density, and show that the state parameter of this dark energy candidate [Formula: see text] should obey the [Formula: see text] constraint, whiles there is no interaction between the fluids filled the universe, and the universe is not in the de Sitter eras. Additionally, based on the thermal fluctuation theory, we study the possibility of inducing fluctuations to the entropy of the DE candidate due to a mutual interaction between the cosmos sectors. Therefore, we find a relation between the thermal fluctuations and the mutual interaction between the cosmos sectors, whiles the DE candidate has a varying energy density. Finally, bearing the coincidence problem in mind, we derive a constraint on the vacuum energy, and investigate its relation with the entropy evolution of the DE candidate. We also point to a model with initial and final de Sitter eras in which a gravitationally induced particle production process leads to change the expansion eras, whiles the corresponding pressure is considered as the cause of current accelerated phase. We study its thermodynamics, and show that such processes may also leave thermal fluctuations into the system. We also find an expression between the thermal fluctuations and the particle production rate. Finally, we use Hayward–Kodama temperature to get a relation for the horizon entropy in models including the gravitationally induced particle production process. Our study shows that the first law of thermodynamics is available on the apparent horizon whiles, the gravitationally induced particle production process, as the DE candidate, may add an additional term to the Bekenstein limit of the horizon. The relation between the validity of the second law of thermodynamics and the gravitationally particle production process is also studied.

Influence of defects on mechanical properties of Ti–6Al–4V components produced by selective laser melting and electron beam melting

Abstract This study evaluates the mechanical properties of Ti–6Al–4 V samples produced by selective laser melting (SLM) and electron beam melting (EBM). Different combinations of process parameters with varying energy density levels were utilized to produce samples, which were analyzed for defects and subjected to hardness, tensile, and fatigue tests. In SLM samples, small pores in amounts up to 1 vol.% resulting from an increase in energy density beyond the optimum level were found to have no major detrimental effect on the mechanical properties. However, further increase in the energy density increased the amount of porosity to 5 vol.%, leading to considerable drop in tensile properties. Samples produced using lower-than-optimum energy density exhibited unmelted powder defects, which, even at 1 vol.% level, strongly affected both tensile and fatigue properties. In EBM, insufficient energy input was found to result in large, macroscopic voids, causing serious degradation in all mechanical properties. These findings are helpful in process optimization and standardization of SLM and EBM processes.

A Novel Cascaded Image Transform by Varying Energy Density to Convert an Image in to Sparse

Background: All natural signals are subjected to sparsity when they are properly represented by a basis function. Sparsity helps us to sample the signals less than Nyquist rate which clearly explained by the recent theory known as compressive sensing. Methods: This paper explains that DFT does a good job in converting the given image into sparse when the energy density of the image is varied and also a cascaded transform DFT and DWT is proposed. Qualitative measures for the cascaded transform were observed to be good. Result: It helps us to convert a given image signal into sparse without loss in information content present in that image. Application: While converting an analog signal into digital, sparsity will help to compress a given analog signal before conversion. So the number of samples obtained by sampling the compressed signal becomes less.

Many-body localization edge in the random-field Heisenberg chain

We present a large scale exact diagonalization study of the one dimensional spin $1/2$ Heisenberg model in a random magnetic field. In order to access properties at varying energy densities across the entire spectrum for system sizes up to $L=22$ spins, we use a spectral transformation which can be applied in a massively parallel fashion. Our results allow for an energy-resolved interpretation of the many body localization transition including the existence of an extensive many-body mobility edge. The ergodic phase is well characterized by Gaussian orthogonal ensemble statistics, volume-law entanglement, and a full delocalization in the Hilbert space. Conversely, the localized regime displays Poisson statistics, area-law entanglement and non ergodicity in the Hilbert space where a true localization never occurs. We perform finite size scaling to extract the critical edge and exponent of the localization length divergence.

The use of pulsed electric fields for accelerating the salting of pork

The efficiency of PEF as a pre-treatment for accelerating the salting (175 kg/m3 NaCl) of pork was assessed through PEF treatments of varying energy densities (22.6–181.1 kJ/kg). This was achieved through a 2 × 2 × 2 factorial design of field strength (1.2 or 2.3 kV/cm), frequency (100 or 200 Hz) and pulse number (150 or 300 pulses). NaCl and water content (kg/kg) acted as indicators for increased saline diffusion. Weight change, pH, cook loss, water-binding capacity (WBC) and texture profiles were also assessed. PEF at 2.3 kV/cm caused greater weight loss than 1.2 kV/cm (p < 0.05). Two treatments (1.2 or 2.3 kV/cm at 100 Hz for 300 pulses) increased the NaCl content of samples (p < 0.05) above the control. A similar trend was evident for cook loss whereby an interaction of 100 Hz and 300 pulses gave the highest value. Within PEF treatments, 100 Hz resulted in greater water content than 200 Hz (p < 0.05). There was no significant effect of PEF on weight change post-curing, WBC or texture profiles of samples. Theses findings indicate that a potential may exist for reduced curing time through PEF, however further work on the optimisation of treatment parameters is required.

The effect of energy density on yield of silicon nanoparticles prepared by pulsed laser ablation in liquid

The effect of energy density on the yield of silicon nanoparticles was studied. Silicon nanoparticles were prepared by laser ablation in ethanol. The yield of nanoparticles was calculated and its results indicate that high energy density led to more nanoparticles production. Particle size was also affected by varying energy density. From TEM images, higher energy density resulted in smaller nanoparticles, which can be explained by nucleation and growth theory. Photoluminescence spectra revealed blue shift of emission peak at high energy density supporting TEM results. Silicon peak was detected by EDS analysis along with oxygen. This means oxidation of silicon might occur within the sample.

Influence of Energy Input on Degradation Behavior of Plastic Components Manufactured by Selective Laser Melting

Additive manufacturing techniques, such as selective laser melting of plastics, generate components directly from a CAD data set without using a specific mold. High building chamber temperatures in combination with long building times lead to physical and chemical degradation of the surrounding powder and the manufactured component in the case of selective laser melting of polyamide 12 (PA12). Thus the following investigations show the influence of energy densities on mechanical properties as well as on the aging behavior of the manufactured components. Therefore several building processes with varying energy densities will be conducted. Aged polymer components were analyzed with physical, thermo analytical and mechanical methods with regards to their process relevant material properties. Considered material properties for example are phase transition temperatures, melting viscosity or molecular weight. The basic understanding of the influence of energy input on material properties will lead to new process strategies with minimized polymer degradation.

Estimating food portions. Influence of unit number, meal type and energy density

Estimating how much is appropriate to consume can be difficult, especially for foods presented in multiple units, those with ambiguous energy content and for snacks. This study tested the hypothesis that the number of units (single vs. multi-unit), meal type and food energy density disrupts accurate estimates of portion size. Thirty-two healthy weight men and women attended the laboratory on 3 separate occasions to assess the number of portions contained in 33 foods or beverages of varying energy density (1.7–26.8kJ/g). Items included 12 multi-unit and 21 single unit foods; 13 were labelled “meal”, 4 “drink” and 16 “snack”. Departures in portion estimates from reference amounts were analysed with negative binomial regression. Overall participants tended to underestimate the number of portions displayed. Males showed greater errors in estimation than females (p=0.01). Single unit foods and those labelled as ‘meal’ or ‘beverage’ were estimated with greater error than multi-unit and ‘snack’ foods (p=0.02 and p<0.001 respectively). The number of portions of high energy density foods was overestimated while the number of portions of beverages and medium energy density foods were underestimated by 30–46%. In conclusion, participants tended to underestimate the reference portion size for a range of food and beverages, especially single unit foods and foods of low energy density and, unexpectedly, overestimated the reference portion of high energy density items. There is a need for better consumer education of appropriate portion sizes to aid adherence to a healthy diet.

Spectroscopic study of gold nanoparticle formation through high intensity laser irradiation of solution

A spectroscopic study of the gold nanoparticle (NP) formation by high-intensity femtosecond laser irradiation of a gold ion solution was reported. The effect of varying energy density of the laser on the formation of gold NPs was also investigated. The surface plasmon resonance (SPR) peak of the gold nanocolloid in real-time UV-visible absorption spectra during laser irradiation showed a distinctive progress; the SPR absorption peak intensity increased after a certain irradiation time, reached a maximum and then gradually decreased. During this absorption variation, at the same time, the peak wavelength changed from 530 to 507 nm. According to an empirical equation derived from a large volume of experimental data, the estimated mean size of the gold NPs varied from 43.4 to 3.2 nm during the laser irradiation. The mean size of gold NPs formed at specific irradiation times by transmission electron microscopy showed the similar trend as that obtained in the spectroscopic analysis. From these observations, the formation mechanism of gold NPs during laser irradiation was considered to have two steps. The first is a reduction of gold ions by reactive species produced through a non-linear reaction during high intensity laser irradiation of the solution; the second is the laser fragmentation of produced gold particles into smaller pieces. The gold nanocolloid produced after the fragmentation by excess irradiation showed high stability for at least a week without the addition of any dispersant because of the negative charge on the surface of the nanoparticles probably due to the surface oxidation of gold nanoparticles. A higher laser intensity resulted in a higher efficiency of gold NPs fabrication, which was attributed to a larger effective volume of the reaction.

4:02 PM Abstract No. 165 - EVLA of lower extremity superficial venous reflux disease: relationship between long-term recanalization rates and energy density

Purpose To determine if energy density (Joules/cm) effects long-term success of EVLA of lower extremity superficial venous reflux. Materials and Methods IRB and HIPAA compliance were obtained. A retrospective review of EVLA treatments performed at a busy outpatient interventional radiology office was performed. Data collected included age, sex, vein segment treated, energy density (J/cm), length of vein treated, ultrasound follow-up intervals, and recanalization. Vein segments treated were divided into 80 J/cm. Comparison of recanalization rates among varying energy density groups were performed. Results There were 2127 vein segments treated from July 2003 to March 2012. Average age of patients were 51.3 years (range 21-86 years) with 1458 women and 347 men treated. Average follow-up was 298.7 days (range 5-1983). Average energy density was 86 J/cm with recanalization rate of 3.24% (69 of 2127). The recanalization rates for 80 J/cm were 5.57% (23 of 413), 4.77% (24 of 502), and 1.82% (22 of 1211) respectively. There is statistically significant lower recanalization rate in the > 80 J/cm group compared to 80 J/cm compared to 60-80 J/cm group almost reached statistical significance (p=0.08). The lower recanalization rate in the 60-80 J/cm group compared to the Conclusion This retrospective review of 2127 vein segments treated showed that EVLA performed with energy density >80 J/cm had the lowest long term recanalization rate. The study suggests that target energy density should be >80 J/cm to obtain highest long term success.

Inhibitory effects of 405 nm irradiation on Chlamydia trachomatis growth and characterization of the ensuing inflammatory response in HeLa cells

BackgroundChlamydia trachomatis is an intracellular bacterium that resides in the conjunctival and reproductive tract mucosae and is responsible for an array of acute and chronic diseases. A percentage of these infections persist even after use of antibiotics, suggesting the need for alternative treatments. Previous studies have demonstrated anti-bacterial effects using different wavelengths of visible light at varying energy densities, though only against extracellular bacteria. We investigated the effects of visible light (405 and 670 nm) irradiation via light emitting diode (LEDs) on chlamydial growth in endocervical epithelial cells, HeLa, during active and penicillin-induced persistent infections. Furthermore, we analyzed the effect of this photo treatment on the ensuing secretion of IL-6 and CCL2, two pro-inflammatory cytokines that have previously been identified as immunopathologic components associated with trichiasis in vivo.ResultsC. trachomatis-infected HeLa cells were treated with 405 or 670 nm irradiation at varying energy densities (0 – 20 J/cm2). Bacterial growth was assessed by quantitative real-time PCR analyzing the 16S: GAPDH ratio, while cell-free supernatants were examined for IL-6 and monocyte chemoattractant protein-1 (CCL2) production. Our results demonstrated a significant dose-dependent inhibitory effect on chlamydial growth during both active and persistent infections following 405 nm irradiation. Diminished bacterial load corresponded to lower IL-6 concentrations, but was not related to CCL2 levels. In vitro modeling of a persistent C. trachomatis infection induced by penicillin demonstrated significantly elevated IL-6 levels compared to C. trachomatis infection alone, though 405 nm irradiation had a minimal effect on this production.ConclusionTogether these results identify novel inhibitory effects of 405 nm violet light on the bacterial growth of intracellular bacterium C. trachomatis in vitro, which also coincides with diminished levels of the pro-inflammatory cytokine IL-6.

Irradiation by light‐emitting diode light as an adjunct to facilitate healing of experimental periodontitis in vivo

This study evaluated the biostimulatory effect of 660 nm light-emitting diode (LED) as an adjunct in the treatment of experimental periodontitis. Ninety-six Sprague-Dawley rats underwent experimental periodontitis by placement of a silk ligature followed with or without additive Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) injection. Irradiation with LED light was performed at varying energy densities of 5, 10 and 15 J/cm2, 1 d after debridement and detoxification. Rats were killed at 3, 7 and 14 d after irradiation with LED light, and the effect of irradiation was evaluated by descriptive histology and quantitative measurements of periodontal bone loss, inflammatory infiltration and cellular proliferation. Reduction of inflammation, accelerated collagen deposition and realignment was noted following irradiation with LED light at densities of 10 and 15 J/cm2, and temporary reduction of periodontal bone loss, as well as bundle bone apposition, was noted at day 3 in rats treated with 10 J/cm2 light. The biomodulatory effect was stronger in sites treated with Pg-LPS injection. In sites without Pg-LPS injection, temporary reduction of inflammation was noted in all LED light-irradiated specimens at day 3. No significant change in cellular proliferation was noted in any LED light-treated group. LED light (660 nm) with an energy density of 10 J/cm2 appeared suitable as an adjunct modality for periodontitis by temporarily reducing inflammation, facilitating collagen realignment and bundle bone deposition. Future studies will aim to amplify the biostimulatory effect of LED light by adding a supplementary medium or repeated irradiation.

Immunohistochemical characterization of phagocytic immune cell infiltration into different adipose tissue depots of dairy cows during early lactation

The present study aimed to investigate whether phagocytic immune cells infiltrate into bovine adipose tissue (AT) and to study the effects of lactation and conjugated linoleic acid (CLA) supplementation on the invasion of phagocytic immune cells into different s.c. and visceral (v.c.) fat depots of primiparous dairy cows during the first 105 d in milk (DIM). German Holstein-Friesian cows (HF; n=25) with a mean body condition score of 3.0 were divided into a control (CON) and a CLA group. From 1 DIM until sample collection, CLA cows were fed 100g of CLA supplement/d (about 6% of c9,t11 and t10,c12 isomers each), whereas the CON cows received 100g/d of a fatty acid mixture instead of CLA. The CON cows (n=5 each) were slaughtered at 1, 42, and 105 DIM, and the CLA cows (n=5 each) were slaughtered at 42 and 105 DIM. Adipose tissues (n=150) from 3s.c. (tailhead, withers, and sternum) and 3 v.c. (omental, mesenteric, and retroperitoneal) depots were sampled. In addition, s.c. tailhead biopsies were collected by repeated surgical biopsies (3 samplings within 7 wk; n=36) from 12 nonpregnant, nonlactating Simmental heifers (SM; mean body condition score=5.0) fed diets of varying energy density to compare the changes in phagocytic immune cell infiltration with early lactating cows. Immunohistochemical analyses of different fat depots revealed a low incidence of phagocytic immune cell infiltration in early lactating cows. The portion of infiltrating macrophages (CD68+) in a few positive AT samples of HF cows was slightly lower in s.c. than v.c. fat and was positively correlated with both empty body weight and adipocyte size. However, no differences with regard to DIM and CLA supplementation were observed in HF cows. Increased accumulation of phagocytic immune cells, albeit at low cell numbers, in nonpregnant, over-conditioned SM heifers might be related to larger adipocytes secreting higher amounts of chemoattractant adipokines compared with the early lactating cows. In conclusion, the extent of fatness in HF cows may not be high enough to stimulate significant infiltration of phagocytic cells in AT and, therefore, these immune cells might have no major role in the immunologic and metabolic adaptations of AT during early lactation.

Effects of Creep Feed with Varied Energy Density Diets on Litter Performance

This study was conducted to evaluate the effects of creep feed with different energy densities on litter performance. A total of 30 sows (LandraceYorkshire) and their litters were randomly assigned with 1, 2, or 3+parities into 1 of 3 treatments (10 sows). Dietary treatments were: i) CON (no creep feed), ii) LE (creep feed (DE 4,000 kcal/kg) from 5 d of age until weaning (21 d)), and iii) HE (creep feed (DE 5,000 kcal/kg) from 5 d of age until weaning). Each piglet was weighed at d 5, 10, 15, 21 (weaning), and d 7 postweaning to determine ADG. Creep feeding reduced concentrations of epinephrine, norepinephrine, and cortisol compared with those in CON group (p

Least-time paths of light

The variational principle in its original form á la Maupertuis is used to delineate paths of light through varying energy densities and to associate shifts in frequency and changes in momentum. The gravitational bending and Doppler shift are in this way found as mere manifestations of least-time energy dispersal. In particular, the general principle of least action due to Maupertuis accounts for the brightness of Type 1a supernovae versus redshift without introducing extraneous parameters or invoking conjectures such as dark energy. Likewise, the least-time principle explains the gravitational lensing without the involvement of additional ingredients such as dark matter. Moreover, time delays along curved geodesics relative to straight paths are obtained from the ratio of the local to global energy density. According to the principle of least action the Universe is expanding uniformly due to the irrevocable least-time consumption of diverse forms of bound energy to the lowest form of energy, i.e. the free electromagnetic radiation.

Fractional CO2 laser: a new therapeutic system forphotobiomodulation of skin remodeling and cytokineproduction in the course of tissue reparation

Eighteen female patients with the signs of photoageing underwent skin rejuvenation using a fractional CO2 laser (SmartXide DOT, DEKA M.E.L.A., Florence, Italy) with varying energy density (2.07, 2.77 and 4.15 J/cm2). Clinical efficacy of the said laser irradiation parameters was assessed in all of the subjects, and the skin cytokine profile was studied by using the immunohistochemistry technique based on skin tissue samples taken prior to the treatment, right after the treatment and in 3 and 30 days. There were significant improvements in the wrinkle and skin texture condition, and hyperpigmentation was reduced as a result of the treatment, which proves the efficacy of using the fractional CO2 laser for the skin photorejuvenation. The technique ensures good clinical results and is distinguished by a short rehabilitation period and excellent safety profile. In the course of the immunohistochemistry, a relation between the skin cytokine production, reepithelization and laser irradiation density was established.