Effect Of Steam Treatment Research Articles

Dynamic modulus of wood containing water-resistant glue finger joint after severe steaming

The effect of steaming treatment on the dynamic modulus of oak wood (Quercus castaneifolia, C. A. Mey.; Fagaceae) containing a water resistant glue-finger joint was investigated. Sample joints were made with two different types of waterproof adhesives, polyurethane (PU) and epoxy, and the samples were tested by a free flexural vibration method according to flexural and longitudinal free vibration modes. Compared with the epoxy joints, the PU finger-joints retained elastic moduli closer to their initial values. In all three vibration tests, finger-jointed oak wood specimens with either glue retained their moduli of elasticity, after the steaming treatments. In the case of longitudinal-tangential (LT) vibration, some increases were observed for the evaluated elastic moduli. After steaming, the obtained dynamic values decreased. For epoxy-bonded specimens, the correlation coefficient in terms of the elastic modulus before and after steaming were weak. There were some acceptable PU-bonded specimens, but there was a considerable decrease after steaming.

Effect of Water Steam Treatment on Extrusion Texturization Product Properties

In this report, we mainly study the effect of water steam pretreatment conditions of raw materials on color, texture parameters, protein quality, solvent retention capacity and other properties of defatted soy flour extrusion texturization product and then trying to establish the regression model. The result shows that the correlation coefficients can be used for predicting the value of L*, hardness, cohesiveness, resilience, WSRC, LASRC, SCSRC and the interaction of covalent bond and non-covalent bond of extruded product of defatted soy flour steam treated. The effect of moisture content of raw material on hardness (p = 0.0010) and LASRC (p = 0.0041) is significant. The temperature of steam treatment on WSRC (p = 0.0017) and the interactions of covalent and non-covalent protein (p = 0.0003) is the most significant impact. The interactive effects of steam treatment temperature and moisture content on SCSRC of product is significant (p = 0.0002). The time of steam treatment has the most significant influence on L* (p = 0.0001), cohesiveness (p = 0.0019) and resilience (p = 0.0008) of product.

Steaming treatment effect on quality of nutritious pasta

Wheat semolina was supplemented with mushroom powder (8%), bengal gram dhal (15%) and defatted soy flour (9%) to prepare nutritious pasta having high protein, high fibre and low calories. Effect of steaming treatment (30 min) on pasta quality with respect to pasting properties, colour and texture was assessed. Results showed that steaming had a significant impact on the rheological properties of pasta starch and improved the cooking quality of pasta by minimizing cooking time and cooking losses. Significant increase in chewiness and springiness resulted in a desirable mouthfeel during eating. Brightness and transparency of product was enhanced with instantization (steaming).

即席麺の蒸し処理が乾燥速度に与える影響

即席麺の蒸し処理が乾燥速度に与える影響

Influence of steam treatment on the properties of particleboard made from oil palm trunk with addition of polyhydroxyalkanoates

This research investigated the effect of steam treatment on the properties of particleboard panels manufactured from oil palm trunk with addition of polyhydroxyalkanoates (PHA) at different percentages. Particles were treated by steam at a temperature of 130°C for 30min. The mechanical and physical properties of the experimental panels including modulus of rupture (MOR), internal bond strength (IB), thickness swelling (TS), water absorption (WA) and surface quality were investigated. Further analyses of the specimens were also conducted using gas chromatography, thermogravimetric analyzer, Fourier transform infrared spectroscopy, X-ray diffraction and field emission scanning electron microscopy. Addition of PHA to oil palm particles enhanced MOR and IB as well as dimensional stability of the panels. The highest MOR and IB values of 8.76MPa and 1.02MPa were determined for the panels made with 10% pure PHA, respectively. It appeared that all properties of the specimens minimally increased with increasing PHA content in the panels. Based on the results of this work PHA could be considered as a potential additive to improve overall properties of such composite panels from oil palm which is an important agricultural crop in Malaysia.

The effect of steam treatment on bonding strength of impregnated wood materials

In wood materials, the species of wood, its humidity, and the type of the adhesive have an important role to make the wood material durable for a long period both in inner space and outer space. In this study, it is aimed to determine the resistance characteristics of adhesive using different impregnation chemicals and different types of adhesives before and after steam treatment. In this study, beech and poplar as wood materials; mixture of Protim-WR 235, Tanalith-C, and Celcure-AC 500 as impregnation materials; and poly vinyl acetate (PVAc), urea formaldehyde (UF), and desmodur vinyl trie ketonol acetate (D-VTKA), resistant to water, as adhesives materials were used. All samples were kept in a steaming equipment for 2, 6, 12, 24, 48, and 96 h, afterwards the maximum force of the samples were measured for each waiting period, and then their bonding strength was determined. According to the results of the study, beech control samples had higher strength than poplar control samples. Control samples bonded with D-VTKA is the least affected one compared to all original control samples in the steam test. D-VTKA can be offered as the proper adhesive for humid places. The results also showed that Tanalith-C is the least affecting impregnation material on the bonding strength.

Steam as a Preplant Soil Disinfestant Tool in California Cut-flower Production

Methyl bromide (MB) has been widely used in California cut-flower production for effective control of a broad range of soil pests, including plant pathogens and weeds. However, MB is an ozone-depleting substance, and its availability to growers is limited according to the Montreal Protocol guidelines. Steam has been suggested as a nonchemical option for preplant soil disinfestation. Five trials were conducted in protected greenhouse structure or open-field cut-flower nurseries in Monterey, San Luis Obispo, and Ventura counties to evaluate the effect of steam application, alone or in combination with solarization, on soilborne plant pathogen populations, weed densities, and crop growth. Several steam application methods were used including steam blanket, spike-hose, buried drip irrigation lines, or drain tile, and these varied among trials. Calla lily (Zantedeschia aethiopica) nursery trials initiated in 2007 and 2008 showed that steam alone or with solarization was similar to or more effective than MB:chloropicrin (MBPic), applied via drip lines, in controlling weeds and Verticillium dahliae at 6-inch depth. Trials conducted in Spring and Fall 2009 in an oriental hybrid lily (Lilium sp.) nursery showed that, 112 days after steam treatment (DAT) in the spring, the steam (spike-hose) treatment had fewer Fusarium oxysporum propagules than the MB treatment. Lily plant growth in the steam-treated plots was similar to MB-treated plots and taller than in control plots. In the fall trial, fewer lily plants emerged by 44 DAT in the untreated control than in steam- and MB-treated plots and steam was not as effective as MB in reducing Pythium populations. In the 2010 sunflower (Helianthus annuus) and bupleurum (Bupleurum griffithii) trial, all steam treatments reduced Pythium and Phytophthora cactorum survival compared with the untreated control plots, whereas weed densities were reduced only in the spike-hose steam-treated plots. These trial studies showed that steam appeared as effective as MB in suppressing pathogens and weeds and improving crop growth in cut-flower nurseries. However, additional information on fuel consumption, treatment time efficiency, and long-term effects of steam treatment on soil health are needed before steam can be recommended as a viable alternative to MB in California cut-flower nurseries.

Effect of steam and lactic acid treatments on the survival of Salmonella Enteritidis and Campylobacter jejuni inoculated on chicken skin

Campylobacteriosis and salmonellosis are the most frequently reported zoonotic infectious diseases. The present work evaluated the effectiveness of steam treatment at 100°C for 8s, a 5% lactic acid treatment for 1min and their combination for inactivating Salmonella Enteritidis and Campylobacter jejuni inoculated on chicken skin. The impact of each treatment on the total aerobic mesophilic bacteria and the effect of rinsing after contact with lactic acid were also evaluated. Residual bacteria were counted immediately after treatment or after seven days of storage at 4°C.Results demonstrated the immediate efficiency of the steam and the combined treatments with reductions of approximately 6 and 5 log cfu/cm2 respectively for S. Enteritidis and C. jejuni. They also showed significant reductions (equal to or >3.2 log cfu/cm2) in the total aerobic mesophilic plate count. Lactic acid had a persistent effect on pathogen growth during storage which was significantly higher when the skin was not rinsed, reaching reductions of 3.8 log cfu/cm2 for both S. Enteritidis and C. jejuni. Only the combined treatments significantly reduced the recovery of the total aerobic mesophilic bacteria during storage.The significant reductions in both pathogens and total aerobic mesophilic bacteria on treated chicken skins are possible ways to improve the safety and shelf life of the product although high levels of indigenous non-pathogenic bacteria may be beneficial due to their protective effect against potential re-contamination of chicken skin.

Effect of steam treatment on catalytic performance of HZSM-5 catalyst for ethanol dehydration to ethylene

The effect of steam treatment on HZSM-5 catalysts was analyzed during ethanol dehydration to ethylene. The parent and the steam treated HZSM-5 catalysts were characterized by various techniques. The results showed that the steam treatment created new mesopores on HZSM-5 zeolites by increasing the treatment temperature, which resulted in the coexistence of micropores and mesopores. The total amount of acid sites and the Brönsted/Lewis ratios of HZSM-5 zeolites decreased after steam treatment, especially for the strong acid sites. The steam treated catalyst at 500°C (HT500) exhibited excellent catalytic stability and good selectivity for ethanol dehydration to ethylene. The improvement in the catalytic stability can be attributed to lower acidity, lower ratio of B/L and newly created mesopores after steam treatment. The analyses of the coke depositions over the spent catalysts indicated that the HT500 catalyst contained less coke deposition than that over the parent HZSM-5 did. The newly created mesopores on catalyst during the steam treatment may accommodate part of coke deposition, suppressing the formation of coke deposition in its inherent micropores to some extent.

Effect of Steam Treatment on Catalytic Performance of La<sub>2</sub>O<sub>3</sub>-HZSM-5 for Methylation of Toluene with Methanol

Methylation of toluene with methanol to synthesize p-Xylene was performed in a fixed-bed reactor. HZSM-5 zeolite as a catalyst was prepared by modification with La2O3. In addition, effect of steam treatment for La2O3-modified HZSM-5 on its catalytic performance was investigated as well. The properties of as-prepared catalysts were characterized by XRD, BET and NH3-TPD. The results indicate that modification with La2O3can narrow the size of HZSM-5 channel effectively. And more than 90% selectivity of p-Xylene is obtained over HZSM-5 with loading of 24% and 30% La2O3. However, above La2O3-modified HZSM-5 with high-selectivity exhibit a poor stability for time on-stream of the methylation reaction. Steam treatment of La2O3-modified HZSM-5 can improve its stability and shape selectivity, decreasing by-products. These effects can be attributed to distortion & narrowing of HZSM-5 channel and reduction of HZSM-5 strong Bronsted acid sites during steam treatment. As a result, the excellent catalytic performance is obtained over 24.0% La2O3-modified HZSM-5 by steam treatment at 773 K for 1.0 h, being 23% conversion of toluene, 93% selectivity of p-Xylene during time on-stream.

Promotion Effect of Steam Treatment on Activity of Ni2P/SiO2 for Hydrodechlorination of Chlorobenzene

Ni 2 P/SiO 2 was pretreated with a 0.8% H 2 O–99.2% H 2 flow at 303, 514, and 543 K. The Ni 2 P/SiO 2 catalysts before and after treatment were characterized by N 2 adsorption-desorption, X-ray diffraction, inductively coupled plasma atomic emission spectrometry, H 2 temperature-programmed desorption, and in situ diffuse reflection infrared Fourier transform spectroscopy, and their activities in the hydrodechlorination of chlorobenzene (CB) were tested in a fix-bed reactor. There was no difference in BET specific surface area, pore structure, the Ni 2 P crystallite size, the Ni content, and the Ni/P ratio for the Ni 2 P/SiO 2 catalysts before and after treatment. The treatment at 303 K did not decrease the density of exposed Ni sites on Ni 2 P/SiO 2 , while the treatment at 514 and 543 K led to the decrease of exposed Ni sites and the increase of the P-OH groups on Ni 2 P/SiO 2 . Under the conditions of 513 K, the CB space velocity of 3.75 ml/(g·h), and the H 2 /CB molar ratio of 9.0, the initial CB conversions on the treated Ni 2 P/SiO 2 catalysts exceeded 93.8%, which was much higher than that (5.6%) on the untreated one. The promotion effect of steam treatment on the activity of Ni 2 P/SiO 2 may be related to a synergism between the Ni sites and the P-OH groups. 在 303, 514 和 543 K 下用 0.8%H 2 O-99.2%H 2 对 Ni 2 P/SiO 2 催化剂进行了水蒸气处理, 利用 N 2 吸附-脱附、X 射线衍射、电感耦合等离子体发射光谱、H 2 程序升温脱附及原位漫反射红外光谱等技术对水蒸气处理前后 Ni 2 P/SiO 2 催化剂的结构进行了表征, 并在常压固定床反应器上评价了其催化氯苯加氢脱氯活性. 结果表明, 经水蒸气处理后, Ni 2 P/SiO 2 催化剂的物相及元素组成、Ni 2 P 晶粒大小、比表面积及孔结构没有明显改变. 与未处理和 303 K 处理的 Ni 2 P/SiO 2 催化剂不同, 513 和 543 K 处理的催化剂表面暴露的 Ni 中心数量减少, 表面 P–OH 基团数量增多. 在 513 K, 氯苯空速 3.75 ml/(g·h) 及 H 2 和氯苯的摩尔比为 9.0 的反应条件下, 经不同温度水蒸气处理的 Ni 2 P/SiO 2 催化剂上氯苯初始转化率高于 93.8%, 约是未预处理催化剂的 17 倍. 这可能与金属 Ni 中心和表面 P–OH 基团的协同作用有关. A promoting effect of steam treatment on the activity of Ni 2 P/SiO 2 for hydrodechlorination of chlorobenzene was found. This is probably related to synergism between Ni sites and P-OH groups.

Effect of steam treatment for the enzymic saccharification of waste mushroom medium after cultivation of shiitake mushroom (Lentinula edodes) and enokitake mushroom (Flammulina velutipes)

Waste mushroom medium of shiitake and enokitake (WS and WE, respectively) was steamed (StmWS and StmWE, respectively) and saccharized with cellulase to obtain glucose which can be feedstock of bioethanol or other bioproducts. Mushroom medium before cultivation of shiitake and enokitake (MS and ME, respectively) was also steamed (StmMS and StmME, respectively) and saccharized to compare with WS and WE. WS was stored at 15 °C for 1 month (SS), and SS was steamed (StmSS) and saccharized. The amount of glucose from StmSS was more than that from StmWS. The cellulose contained in StmSS and StmWE was saccharified earlier than that in StmMS and StmME, respectively. When StmSS and StmWE-added Meicelase of 5 and 3 FPU/g substrate (9.7 and 5.8 mg Meicelase/g substrate), respectively, was saccharized for 120 h, the saccharification ratio (the amount of glucose saccharized from cellulose/theoretical amount of glucose from cellulose) of them exceeded 80 %. The amount of glucose obtained from StmSS and StmWE was 311.0 and 207.7 mg/g substrate under the condition. It was found that the cellulose contained in mushroom medium was saccharized with less amount of cellulase by the influence of cultivation of shiitake or enokitake, storage of shiitake, and steaming.

The influence of steam cleaning procedures on the surface roughness of commonly used type III dental stone for the fabrication of removable dentures

This study investigated the possible detrimental effects of steam treatment on the surface of type III dental stone, which is a common laboratory material used for the construction of removable dentures. Forty dental stone specimens were prepared and divided into four groups (A, B, C and D), and group A was used as the control group. The other groups were treated with steam from a standard distance for varying durations (30, 60 and 120 s). The duration of steam cleaning significantly increased Ra values (F = 63.150, p = 0.000). Similarly, the duration of steam application was directly correlated with the weight changes (F = 17.721, p = 0.000). A significant amount of dental stone can be removed from the surface while treating with steam. These studies demonstrated that expanded periods of steam cleaning cause weight loss and abrade the surface of type III dental stones; therefore, these devices should be used with caution during denture fabrication procedures.

Effect of Steam Treatment on Pellet Strength and the Energy Input in Pelleting of Softwood Particles

Three whitewood species (spruce, Douglas fir, and pine) and one sample of bark (Douglas fir) were treated with high-pressure steam at 220C for 5 min. The steam treatment resulted in a reduction in average particle size by as much as 25%. Pine particles showed the largest reduction in size, while bark showed the least. Despite a slightly lower density, pellets made from treated particles had a higher mechanical strength (hardness) than untreated pellets. The mechanical energy required to compact steam-treated material was higher than the energy required to make pellets from untreated wood. Douglas fir required the least energy input among debarked samples. Spruce was the stickiest pellet to be pushed out of the cylindrical die. Bark pellets required the lowest energy to be compacted and pushed out of the cylindrical die. The overall conclusion is that steam treatment reduces particle size, reduces pellet density slightly, but increases the mechanical strength of the produced pellets. Steam treatment increases the energy input required to make pellets, and more energy is required to push pellets out of the die compared to pellets made from untreated biomass.

Methane dehydro-aromatization over Mo/HZSM-5 catalysts in the absence of oxygen: Effect of steam-treatment on catalyst stability

The effect of steam-treatment to HZSM-5 zeolite and Mo/HZSM-5 with a steaming time range of 0.5-1 h on the catalytic performance of methane dehydro-aromatization (MDA) over Mo/HZSM-5 catalyst prepared with impregnation has been studied in detail in combination with the characterization of 1H MAS NMR technique. Both the deactivation rate constant ( kd) and the Brönsted acid sites per unit cell were calculated to quantitatively evaluate the stability of Mo/HZSM-5 catalysts treated with steam at 813 K before and after impregnation of molybdenum species, and the corresponding variation of their Brönsted acid sites. The results reveal that a V-shape relationship between kd and the number of Bl acid sites per unit cell is presented on Mo/HZSM-5 catalyst under the tested steam-treatment and reaction conditions.

Effect of steaming treatment on resistance to footprints in Turkey oak wood for flooring

Turkey oak (Quercus cerris L.) wood has some technological limitations that reduce its market value despite its great potential. This study evaluated the effect of indirect steaming on the resistance to footprints of Turkey oak wood in order to assess its use as parquet. Steaming treatments were carried out on green wood at 120°C and for 24 hours, while a drying process was carried out on all boards at 63°C, 120 mm Hg of vacuum for 34 days. Good elastic restoration was observed for untreated wood, while for treated wood the resistance to footprints was higher in the radial than in the tangential direction. By contrast, a significant negative effect on the elastic recovery of the original dimensions was found which was higher in radial than in tangential direction, when a load was conducted on steamed wood.

Effect of Steam Treatment on the Properties of Wood Cell Walls

Steam treatment is a hygrothermal method of potential industrial significance for improving the dimensional stability and durability of wood materials. The steaming results in different chemical and micromechanical changes in the nanostructured biocomposite that comprise a wood cell wall. In this study, spruce wood ( Picea abies Karst.) that had been subjected to high-temperature steaming up to 180 °C was examined, using imaging Fourier Transform Infrared (FT-IR) microscopy and nanoindentation to track changes in the chemical structure and the micromechanical properties of the secondary cell wall. Similar changes in the chemical components, due to the steam treatment, were found in earlywood and latewood. A progressive degradation of the carbonyl groups in the glucuronic acid unit of xylan and a loss of mannose units in the glucomannan backbone, that is, a degradation of glucomannan, together with a loss of the C═O group linked to the aromatic skeleton in lignin, was found. The development of the hygroscopic and micromechanical properties that occurred with an elevation in the steam temperature correlated well with this pattern of degradation in the constituents in the biocomposite matrix in the cell wall (hemicellulose and lignin).

XPS and IGC characterization of steam treated triticale straw

The surface chemical composition and surface energy of native and steam treated triticale straws have been investigated by X-ray photoelectron spectroscopy (XPS) and inverse gas chromatography (IGC) to reveal the effect of steam treatment temperature and time. The XPS results show that the contents of C elements and C–C group on the exterior surface of native triticale straw are much higher than those on the interior surface, indicating that there was a high quantity of wax on the exterior surface of the native triticale straw. Upon steam treatment, both carbon levels and C–C groups reduce with increasing steam temperature and treatment time of the exterior surfaces. However, the effect of steam treatment on the interior surface is very limited. In terms of the surface acid and base properties, the steam treated samples exhibited higher acid and base properties than the native sample, indicating a more polar surface of the steam treated sample.

Effect of steam treatment on soluble phenolic content and antioxidant activity of the Chaga mushroom (Inonotus obliquus)

Abstract The effect of steam treatment on free phenolic acids in Chaga mushrooms (Inonotus obliquus) was investigated. Untreated and steam-treated (120 °C, 3 h) samples of I. obliquus were extracted with organic solvents and free phenolic acid-containing fractions were isolated. Free phenolic acids were determined by LC/PDA (liquid chromatography/photodiode array), ESI LC/MS (electrospray ionisation liquid chromatography/mass spectrometry), and GC/MS (gas chromatography/mass spectrometry). After the steam treatment, the soluble phenolic content determined by modified Folin–Ciocalteu method was increased and antioxidant activity was enhanced, as confirmed by a DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity assay. The amounts of vanillic acid, protocatechuic acid, syringic acid, and 2,5-dihydroxyterephthalic acid were increased significantly as the result of the steam treatment, suggesting that the liberation of low molecular weight free phenolics was enhanced by the steaming process. Consequently, the radical scavenging activity was also significantly enhanced by free phenolics produced using this method.

Methods for improving volume stability of steel slag as fine aggregate

Suitable methods for enhancing the volume stability of steel slag utilized as fine aggregate were determined. The effects of steam treatment at 100 °C and autoclave treatment under 2.0 MPa on the soundness of steel slag sand were investigated by means of powder ratio, linear expansion, compressive and flexural strength. DTA, EDX, XRD and ethylene glycol methods were employed to analyze both the treated slags and susceptible expansion grains. Experimental results indicate that powder ratio, content of free lime and rate of linear expansion can express the improvement in volume stability of different treated methods. Steam treatment process cannot ultimately prevent specimens from cracking and decrease of strength, but mortar made from autoclave treated slag keeps integration subjected to hot water of 80 °C until 28 d and its strength do not show significant decrement. The hydration of over-burn free lime and periclase phase are the main cause for the disintegration or crack of untreated and steam treated steel slag’s specimens. Autoclave treatment process is more effective than steam treatment process on enhancement of volume stability of steel slag.