Um experimento foi realizado com o objetivo de avaliar diferentes alternativas nutricionais no controle de diarréia de leitões. Foram utilizados 128 leitões de uma linhagem comercial, desmamados com idade média de 21 dias, sendo metade de cada sexo. Os leitões foram distribuídos em 32 baias, sendo cada unidade experimental composta por quatro leitões. O delineamento experimental foi o de blocos ao acaso, com os animais distribuídos em oito tratamentos e quatro repetições de quatro animais (dois machos e duas fêmeas). Tratamentos: T1 - alto calcário, sem óxido de zinco, sem ácido benzóico; T2 - alto calcário, com óxido zinco, sem ácido benzóico; T3 - baixo calcário, sem óxido de zinco, sem ácido benzóico; T4 - baixo calcário, com óxido zinco, sem ácido benzóico; T5 - alto calcário, sem óxido zinco, com ácido benzóico; T6 - alto calcário, com óxido de zinco, com ácido benzóico; T7 - baixo calcário, sem óxido de zinco, com ácido benzóico; T8 - baixo calcário, com óxido de zinco, com ácido benzóico. As dietas foram fornecidas em dois períodos: de 1 a 14 dias pós-desmame (Fase I) e de 15 a 28 dias pós-desmame (Fase II). A partir do 29º dia os animais receberam uma mesma dieta até os 70 dias de idade. As características zootécnicas avaliadas foram: o ganho de peso, o consumo de ração, índice de conversão alimentar e a incidência de diarréia. Além disso, foram avaliadas a altura das vilosidades do duodeno, a profundidade das criptas e a relação altura de vilosidades/profundidade de cripta. Ao final do experimento, foi coletada a tíbia para a avaliação da densidade óssea. O óxido de zinco diminuiu a incidência de diarréia e foi mais eficiente em melhorar o GPMD e o CRMD de 1 a 14 dias pós-desmame. O ácido benzóico associado ao baixo calcário melhorou o GPMD de 15 a 28 dias pós-desmame e teve efeito positivo na morfologia duodenal. A diminuição do nível de calcário não prejudicou a densidade mineral óssea dos animais. / One trial was conducted to evaluate different nutritional alternatives for diarrhea control in weanling piglets. One hundred twenty eight piglets (half male and half female) were weaned with approximately 21 days of age. The piglets were distributed in 32 pens and each one was an experimental unit with four piglets. In a block design, the animals were distributed in eight treatments and four replications with four animals each (two male and two female). Treatments: T1 - high limestone, without zinc oxide and benzoic acid; T2 - high limestone, with zinc oxide and without benzoic acid; T3 - low limestone, without zinc oxide and benzoic acid; T4 - low limestone, with zinc oxide and without benzoic acid; T5 - high limestone, without zinc oxide and with benzoic acid; T6 - high limestone, with zinc oxide and benzoic acid; T7 - low limestone, without zinc oxide and with benzoic acid; T8 - low limestone, with zinc oxide and benzoic acid. The diets were given in two periods: d 1 - 14 postweaning (Phase I) and d 15 - 28 postweaning (Phase II). The animals were fed with common diet from d 29 until 70 days of age. Parameters evaluated were: body weight gain, fed conversion, and diarrhea incidence. In addition, duodenum\'s villus height, crypt depth, and villus height/crypt depth were evaluated. At the end of time trial, tibia was collected for bone density analyze. Zinc oxide reduced diarrhea incidence and improved GDW and DC from d 1 - 14 postweaning. Benzoic acid with low limestone level improved GDW from d 15 - 28 postweaning and duodenal morphology was affected positively. The lower level of limestone did not affect mineral bone density of the animals.

Abstract not available

The aim of the present investigation is to increase theunderstanding of the role played by the solvent in inhibitingor enhancing crystal growth. Drowning-out crystallizationexperiments has been performed by the controlled addition ofwater or ethanol water mixtures to a saturated solution ofbenzoic acid in ethanol-water mixtures. Crystal habitcontrolling factors have been identified.Seededcrystallization experiments have been carried out to evaluatethe effect of solvent composition on crystal habit at constantsupersaturation. The solubility of benzoic acid inethanol-water mixtures at the working temperatures has beendetermined. Electro-zone sensing determinations and microscopicmeasurements are used to characterize the final crystallineproduct. It has been found that the shape of the benzoic acidcrystals grown from ethanol-water solutions ranges from needlesto platelets. Platy particles possess a predominant basal plane(001), bound by (010) and (100) faces, while needles aredeveloped along the b-axis. Long needle-shaped particles havebeen produced at low initial bulk concentration and highethanol concentration in the feed. Small platelets are obtainedat high initial bulk concentrations and high waterconcentration in the feed. The effect of solvent composition on the growth rate hasbeen evaluated at constant supersaturation. Seed crystals arecharacterized by image analysis measurement both before andafter each experiment. Length and width dimensions have beenmeasured on the particle silhouette. The growth rate, thesolid-liquid interfacial energy and the surface entropy factorfor the (010) faces (length dimension) and (100) faces (widthdimension) have been estimated. The interfacial energy andsurface entropy factor decreases in the direction of increasingethanol concentration due to increasing solubility. The results suggest that at low ethanol concentration(xEtOH&lt;60%) growth proceeds by screw dislocation mechanism,and adsorption of ethanol molecules may reduce the growth rate.As the ethanol concentration increases above a critical value(xEtOH ≥60%), the growth mechanism shifts to surfacenucleation and the growth rate increases with increasingethanol concentration. It has been suggested that the observedeffect of the solvent composition on crystal habit is theresult of two conflicting effects here referred as the kineticand interfacial energy effects. High interactions of the pairethanol-benzoic acid seem to be responsible of the growthretardation (kinetic effect) exerted by the solvent. On theother hand, increased ethanol concentration leads to reduceinterfacial energy and increasing surface nucleation whichmight contribute to enhance growth kinetics. <b>Keywords:</b>drowning-out crystallisation, solventcomposition, benzoic acid, solubility, crystal growth,interfacial energy, surface entropy factor, growth mechanism,crystal shape distribution.

<p>The aim of the present investigation is to increase theunderstanding of the role played by the solvent in inhibitingor enhancing crystal growth. Drowning-out crystallizationexperiments has been performed by the controlled addition ofwater or ethanol water mixtures to a saturated solution ofbenzoic acid in ethanol-water mixtures. Crystal habitcontrolling factors have been identified.Seededcrystallization experiments have been carried out to evaluatethe effect of solvent composition on crystal habit at constantsupersaturation. The solubility of benzoic acid inethanol-water mixtures at the working temperatures has beendetermined.</p><p>Electro-zone sensing determinations and microscopicmeasurements are used to characterize the final crystallineproduct. It has been found that the shape of the benzoic acidcrystals grown from ethanol-water solutions ranges from needlesto platelets. Platy particles possess a predominant basal plane(001), bound by (010) and (100) faces, while needles aredeveloped along the b-axis. Long needle-shaped particles havebeen produced at low initial bulk concentration and highethanol concentration in the feed. Small platelets are obtainedat high initial bulk concentrations and high waterconcentration in the feed.</p><p>The effect of solvent composition on the growth rate hasbeen evaluated at constant supersaturation. Seed crystals arecharacterized by image analysis measurement both before andafter each experiment. Length and width dimensions have beenmeasured on the particle silhouette. The growth rate, thesolid-liquid interfacial energy and the surface entropy factorfor the (010) faces (length dimension) and (100) faces (widthdimension) have been estimated. The interfacial energy andsurface entropy factor decreases in the direction of increasingethanol concentration due to increasing solubility.</p><p>The results suggest that at low ethanol concentration(xEtOH<60%) growth proceeds by screw dislocation mechanism,and adsorption of ethanol molecules may reduce the growth rate.As the ethanol concentration increases above a critical value(xEtOH ≥60%), the growth mechanism shifts to surfacenucleation and the growth rate increases with increasingethanol concentration. It has been suggested that the observedeffect of the solvent composition on crystal habit is theresult of two conflicting effects here referred as the kineticand interfacial energy effects. High interactions of the pairethanol-benzoic acid seem to be responsible of the growthretardation (kinetic effect) exerted by the solvent. On theother hand, increased ethanol concentration leads to reduceinterfacial energy and increasing surface nucleation whichmight contribute to enhance growth kinetics.</p><p><b>Keywords:</b>drowning-out crystallisation, solventcomposition, benzoic acid, solubility, crystal growth,interfacial energy, surface entropy factor, growth mechanism,crystal shape distribution.</p>

<p>Spherical agglomerates of benzoic acid crystals have been successfully prepared by drowning-out crystallization in three solvent partial miscible mixtures. Benzoic acid is dissolved in ethanol, bridging liquid is added and this mixture is fed to the agitated crystallizer containing water. Fine crystals are produced by crystallization of the substance, and the crystals are agglomerated by introduction of an immiscible liquid called the bridging liquid. The concentration of solute, agitation rate, feeding rate, amount of bridging liquid and temperature are found to have a significant influence on the physico-mechanical properties of the product. The product particle characterization includes the particle size distribution, morphology and mechanical strength.</p><p>Many of the solvents such as chloroform, toluene, pentane, heptane, cyclo hexane, diethyl ether and ethyl acetate were used as bridging liquids. Among the selected solvents ethyl acetate and di ethyl ether could not form the spherical agglomerates. Characteristics of the particles are changing with the bridging liquid used. Range of the operation for spherical agglomeration is very narrow and was shown that only at certain conditions the spherical agglomerates are produced. Increased amount of bridging liquid, decrease in feeding rate and temperature causes the particle size to increase. Particle morphology depends on the bridging liquid used, amount of bridging liquid and the temperature. Particles look completely spherical from the experiments where toluene is used as bridging liquid. </p><p>The mechanical strength of single agglomerates has been determined by compression in a materials testing machine, using a 10N load cell. For single particle compression an approximate estimation of the true stress is presented. Compression characteristics for single agglomerates are compared with data on particle bed compression. Low elastic recovery and high compressibility of the single particles and of bed of particles reveals that the spherical agglomerates prepared in this work have a plastic behavior which is expected to be favorable for direct tabletting. Some of the stress–strain curves are J-shaped with no clear fracturing of the particles, and are well correlated by an exponential–polynomial equation. </p>

Um experimento foi realizado com o objetivo de avaliar diferentes alternativas nutricionais no controle de diarréia de leitões. Foram utilizados 128 leitões de uma linhagem comercial, desmamados com idade média de 21 dias, sendo metade de cada sexo. Os leitões foram distribuídos em 32 baias, sendo cada unidade experimental composta por quatro leitões. O delineamento experimental foi o de blocos ao acaso, com os animais distribuídos em oito tratamentos e quatro repetições de quatro animais (dois machos e duas fêmeas). Tratamentos: T1 - alto calcário, sem óxido de zinco, sem ácido benzóico; T2 - alto calcário, com óxido zinco, sem ácido benzóico; T3 - baixo calcário, sem óxido de zinco, sem ácido benzóico; T4 - baixo calcário, com óxido zinco, sem ácido benzóico; T5 - alto calcário, sem óxido zinco, com ácido benzóico; T6 - alto calcário, com óxido de zinco, com ácido benzóico; T7 - baixo calcário, sem óxido de zinco, com ácido benzóico; T8 - baixo calcário, com óxido de zinco, com ácido benzóico. As dietas foram fornecidas em dois períodos: de 1 a 14 dias pós-desmame (Fase I) e de 15 a 28 dias pós-desmame (Fase II). A partir do 29º dia os animais receberam uma mesma dieta até os 70 dias de idade. As características zootécnicas avaliadas foram: o ganho de peso, o consumo de ração, índice de conversão alimentar e a incidência de diarréia. Além disso, foram avaliadas a altura das vilosidades do duodeno, a profundidade das criptas e a relação altura de vilosidades/profundidade de cripta. Ao final do experimento, foi coletada a tíbia para a avaliação da densidade óssea. O óxido de zinco diminuiu a incidência de diarréia e foi mais eficiente em melhorar o GPMD e o CRMD de 1 a 14 dias pós-desmame. O ácido benzóico associado ao baixo calcário melhorou o GPMD de 15 a 28 dias pós-desmame e teve efeito positivo na morfologia duodenal. A diminuição do nível de calcário não prejudicou a densidade mineral óssea dos animais. / One trial was conducted to evaluate different nutritional alternatives for diarrhea control in weanling piglets. One hundred twenty eight piglets (half male and half female) were weaned with approximately 21 days of age. The piglets were distributed in 32 pens and each one was an experimental unit with four piglets. In a block design, the animals were distributed in eight treatments and four replications with four animals each (two male and two female). Treatments: T1 - high limestone, without zinc oxide and benzoic acid; T2 - high limestone, with zinc oxide and without benzoic acid; T3 - low limestone, without zinc oxide and benzoic acid; T4 - low limestone, with zinc oxide and without benzoic acid; T5 - high limestone, without zinc oxide and with benzoic acid; T6 - high limestone, with zinc oxide and benzoic acid; T7 - low limestone, without zinc oxide and with benzoic acid; T8 - low limestone, with zinc oxide and benzoic acid. The diets were given in two periods: d 1 - 14 postweaning (Phase I) and d 15 - 28 postweaning (Phase II). The animals were fed with common diet from d 29 until 70 days of age. Parameters evaluated were: body weight gain, fed conversion, and diarrhea incidence. In addition, duodenum\'s villus height, crypt depth, and villus height/crypt depth were evaluated. At the end of time trial, tibia was collected for bone density analyze. Zinc oxide reduced diarrhea incidence and improved GDW and DC from d 1 - 14 postweaning. Benzoic acid with low limestone level improved GDW from d 15 - 28 postweaning and duodenal morphology was affected positively. The lower level of limestone did not affect mineral bone density of the animals.

This diploma thesis deals with photoelectrochemical cells containing photoactive titanium dioxide anode and their use for photocatalytic degradation of organic compound from water solutions. The electrical properties of the produced photoelectrochemical cells were determined by the use of voltamperometric characteristics, the oxidation ability of the cells was monitored by measuring the fluorescence of the oxidative intermediates. To study these reactions, benzoic acid was used as the fluorescence probe for OH˙ radicals. The aim of the study was to study the influence of material composition and spatial arrangement of the cathode and the relationship between irradiation, current and rate of electrode processes.

Spherical agglomerates of benzoic acid crystals have been successfully prepared by drowning-out crystallization in three solvent partial miscible mixtures. Benzoic acid is dissolved in ethanol, bridging liquid is added and this mixture is fed to the agitated crystallizer containing water. Fine crystals are produced by crystallization of the substance, and the crystals are agglomerated by introduction of an immiscible liquid called the bridging liquid. The concentration of solute, agitation rate, feeding rate, amount of bridging liquid and temperature are found to have a significant influence on the physico-mechanical properties of the product. The product particle characterization includes the particle size distribution, morphology and mechanical strength. Many of the solvents such as chloroform, toluene, pentane, heptane, cyclo hexane, diethyl ether and ethyl acetate were used as bridging liquids. Among the selected solvents ethyl acetate and di ethyl ether could not form the spherical agglomerates. Characteristics of the particles are changing with the bridging liquid used. Range of the operation for spherical agglomeration is very narrow and was shown that only at certain conditions the spherical agglomerates are produced. Increased amount of bridging liquid, decrease in feeding rate and temperature causes the particle size to increase. Particle morphology depends on the bridging liquid used, amount of bridging liquid and the temperature. Particles look completely spherical from the experiments where toluene is used as bridging liquid. The mechanical strength of single agglomerates has been determined by compression in a materials testing machine, using a 10N load cell. For single particle compression an approximate estimation of the true stress is presented. Compression characteristics for single agglomerates are compared with data on particle bed compression. Low elastic recovery and high compressibility of the single particles and of bed of particles reveals that the spherical agglomerates prepared in this work have a plastic behavior which is expected to be favorable for direct tabletting. Some of the stress–strain curves are J-shaped with no clear fracturing of the particles, and are well correlated by an exponential–polynomial equation. / QC 20101119

Benzoyl peroxide (BPO) is a common bleaching agent used in wheat flour. Due to its ability to damage existing nutrients in food and potential adverse effect to health, BPO have been strictly banned as a food additive in several countries and regions, such as China and Europe. However, the United States specifies that BPO is generally recognized as safe (GRAS). So, the WHO/FAO created a Codex Alimentarius Commission (CAC) to regulate the international BPO usage standard. According to the CAC, it is restricted at 75 mg/kg or parts per million (ppm). BPO is very unstable and easily converts to benzoic acid (BA), which places the analytical challenge for accurate BPO quantification. The objective of this study is to develop a reliable method for BPO quantification in flour. Raman spectroscopy was first explored to detect BPO and BA on an aluminum foil slide. The result showed BPO and BA produced distinct Raman peaks that can be discriminated against. However, the sensitivity was not satisfactory to reach the regulation limit. To improve sensitivity, surface-enhanced Raman spectroscopy (SERS) was applied using silver nanoparticles as the substrate. Although the signals did enhance significantly using SERS, the characteristic peaks of BPO disappeared as BPO converted to BA during the sample preparation. We then went back to Raman spectroscopy but focused on optimizing the sample preparation to enhance the signal intensity. Using a hydrophobic surface (i.e., parafilm) which can hold the droplet and minimize the spread, the Raman signal was enhanced significantly after repeating multiple droplets on the same surface. A standard curve was created for BPO from 25 ppm to 250 ppm and for BA from 250 ppm to 1000 ppm, respectively. To detect BPO in wheat flour, we applied a more advanced Raman imaging instrument and focused on the analysis of Raman maps instead of spectra for the analysis of effect flour matrix to BPO extraction and detection. We firstly tried an in situ method, which scanned the pellet of flour spiked with different amounts of BPO without extraction. However, we could not detect BPO at 0.1% or lower in flour samples. We then tried an extraction method using acetonitrile as the solvent, which showed a lower detection limit compared to the in situ method. However, this extraction method yielded inconsistent results for BPO that is under 0.05% in flour. The extraction method developed was further improved with an evaporating step and a C18 solid phase extraction (SPE) spin column. This improved the extraction efficacy and provided a roughly 60% recovery percentage for detecting BPO in wheat flour without decomposing into BA. In conclusion, we developed a simple sample preparation protocol coupled with Raman spectroscopy to quantify BPO in flour without converting to BA, which would meet the regulation requirement. This method also shortened the experiment time including both sample preparation and detection time compared to current methods.

no / The synthesis and crystal structure of the lithium hydrate salt of the charge transfer complex between 3,5-dinitrobenzoic acid and 4-(dimethylamino) benzoic acid is reported. It is the first crystal structure reported for such a class of hybrid inorganic/organic material. The design principles may have utility in the future creation of new ternary and higher complexes.