CUTTING FORCES IN HIGH SPEED TAPPING CAST IRON BY TUNGSTEN CARBIDE TAPS

The engineblock production lines need high speed tapping with tungsten carbide taps. In the tapping process, the machining precision and the tool life of taps are directly influenced by tapping forces. And the parameter optimization of tap structures is also correlated with the variation of tapping forces. Therefore, the study of tapping forces is necessary in developing new style taps. Several experiments about some novel carbide taps are performed on a vertical machining center by a Kistler dynamometer system in blind tapping both gray cast iron and ductile cast iron. And the variations of tapping forces are analyzed in tapping-in and tapping-out periods. It indicates that cutting forces hardly vary with the tap wear in tapping cast iron. Contrarily, tapping forces are closely correlated with the holding method. Besides, it also depends on the helix angle, the flute numbers and the plasticity of the work material to some extent.

HR-HPV感染合并CIN与阴道微环境、TAP1及TAP2基因多态性的关系研究

目的探讨高危型人乳头瘤病毒(HR-HPV)感染合并宫颈上颈上皮内瘤变(CIN)与阴道微环境、TAP1及TAP2基因多态的关系。方法收集2022年5月至2024年5月宁波大学附属第一医院收治的HR-HPV感染患者120例,行液基薄层细胞学检测或宫颈活检,合并CIN 75例(HR-HPV感染合并CIN组),不合并CIN 45例(HR-HPV感染组)。采集宫颈阴道分泌物,运用16S rRNA技术进行测序,比对Greengene数据库,以“门、属”水平分析两组阴道微环境菌群分布;收集外周静脉血行聚合酶链式反应扩增TAP1及TAP2基因多态性片段,分析HR-HPV感染合并CIN与TAP1、TAP2基因多态性的关系。结果“门”水平上,HRHPV感染合并CIN组厚壁菌门相对丰度低于HR-HPV感染组,放线菌门、拟杆菌门、变形菌门、软壁菌门及梭杆菌门均高于HR-HPV感染组(均P<0.05);“属”水平上,HR-HPV感染合并CIN组乳酸杆菌属低于HR-HPV感染组,加德纳菌属、普氏菌属、奇异菌属、脲原体属、纤毛菌属、链球菌属及厌氧球菌属均高于HRHPV感染组(均P<0.05)。两组TAP1、TAP2基因多态性位点理论值与实际值差异均无统计学意义(均P>0.05);两组TAP1 rs41549617位点基因型分布差异有统计学意义(P<0.05),且HR-HPV感染合并CIN组AA基因型、A等位基因频率高于HR-HPV感染组(均P<0.05);两组TAP2 rs1135216位点基因型分布差异无统计学意义(P>0.05)。结论HR-HPV感染患者可因阴道微生物菌群变化以及TAP1 rs41549617位点改变进一步发展为CIN,检测阴道微生物菌群以及TAP1 rs41549617位点有助于对HR-HPV感染患者进行风险分层,以便制定个体化随访策略。

MCUS联合CYFRA21-1、TAP及SCCA检测在食管癌术前分期诊断中的应用

目的分析微探头超声内镜(MCUS)联合细胞角蛋白19片段抗原(CYFRA21-1)、肿瘤异常蛋白(TAP)及鳞状细胞癌抗原(SCCA)检测在食管癌术前分期诊断中的应用价值。方法选取2020年8月至2022年11月期间于郑州大学第一附属医院进行治疗的食管癌患者137例为研究对象。以病理分期为金标准,分析MCUS分期与病理学分期的关系;对比血清CYFRA21-1、SCCA水平以及TAP阳性表达与病理特征、MCUS分期的关系;分析血清CYFRA21-1、SCCA水平、TAP阳性表达联合MCUS分期对食管癌病理学分期的诊断价值。结果MCUS诊断食管癌病理学分期的综合准确率为88.89%。血清CYFRA21-1、SCCA水平:T_(3-4)>T_(1-2)、低分化>高、中分化、Ⅲ~Ⅳ期>Ⅰ~Ⅱ期、MCUS分期T_(4)>T_(3)>T_(1)、T_(2),差异具有统计学意义(P<0.05);不同病理学分期、分化程度、TNM分期以及MCUS分期的TAP阳性率比较,差异无统计学意义(P>0.05)。血清CYFRA21-1、SCCA水平、TAP阳性表达联合MCUS检查对食管癌病理学分期判断的准确率提高至95.62%。结论MCUS联合血清CYFRA21-1、SCCA水平及TAP检测可准确诊断食管癌术前分期,可为临床治疗食管癌提供可靠依据。

超声引导下TAP阻滞对妇科腹腔镜手术患者麻醉效果及术后镇痛的影响

目的 探讨超声引导下TAP阻滞技术应用于妇科腹腔镜手术的麻醉效果及在术后镇痛方面的优势。方法 选取100例腹腔镜手术患者,根据随机数字表法将患者分为两组,每组50例。对照组应用常规静脉镇痛干预,试验组采用超声引导下TAP阻滞麻醉。比较两组患者心率、血压水平、手术麻醉效果、术后疼痛评分与镇痛状况。结果 试验组患者心率、血压水平、手术麻醉效果及术后疼痛评分与镇痛状况均明显优于对照组(P<0.05)。结论 超声引导下TAP阻滞可用于腹腔镜手术,对妇科疾病的手术治疗有着较为突出的麻醉作用,值得临床推广与应用。

Determination of optimum tapping date for gum arabic production in South Kordofan State, Sudan

Acacia senegal, the gum arabic producing tree, is the most important tree species for the livelihood of the people in South Kordofan State, Sudan. The objective of this study was to determine the optimum tapping date for gum arabic production in the study area. A randomized complete block design experiment with three replications was conducted at （Mead） area for two continuous growing seasons 2008/2009 - 2009/2010. The treatments comprised six tapping dates （1 Oct, 15 Oct, 1 Nov, 15 Nov, 1 Dec, and 15 Dec）. Results ishowed highly significant differences （p 〈 0.001） in gum arabic yield （g／tree） in all pickings and in the total gum yield between the tapping dates. The results also showed that tapping of trees on 15 October and 1 November gave a higher yield compared to the other dates. The highest gum yield of 1086.6 and 661.2 g/tree was recorded on 15 October and 15 November, while the lowest gum yield of 297.9 g/tree was recorded when the trees were tapped on 1 October. The two highest-yield dates of tapping （15 Oct and 1 Nov） are recommended as the best time for tapping for gum arabic production in South Kordofan State. These results can be used to increase gum arabic production and farmer income in South Kordofan State.

Ultrasonic-assisted vibration tapping using taps with different coatings

A machine vision for assessing and inspecting the ratio of thread areas associated with fixed frequency (FF) and limited tracing frequency (LTF) ultrasonic-assisted vibration was presented using differently coated taps after tapping of Ti-6Al-4V alloys.Experimental results indicate that TiAlN Micran taps yield the best tapping quality for different coatings and tapping conditions.TiAlN Micran coated taps with LTF make the largest improvement over traditional tapping (TT),with an average increase of 30.2%.

Standardized gum tapping techniques to maximize yield from high-value Indian tree,Sterculia urens

Industrial applications of natural gums have been expanding tremendously, so gum collection from trees provides an important livelihood for local dwellers in drought-prone Rajasthan and its surroundings states. Traditional gum tapping is crude and unscientific; deep incision, untimely extraction and high concentration of chemicals in gum have affected Sterculia urens species in its natural habitat. In studies 2 years on trees having diameter at breast height 〉40 cm from natural stands to maximize gum collection and standardize the tapping method （bore holes vs. V blazes）, tapping season, chemical and concentration, different tapping techniques were tes- ted. For tapping maximum gum was collected using bore hole. Ethephon was better as extraction chemical than sulphuric acid. Bore-hole tapping with a 5-cm hole and ethephon at 300 mg/mL yielded the most gum （135.20 g/ tree）. Ethephon at 300 mg/mL yielded the most gum. Ethephon induced gummosis without affecting the health of tree. Tapping seasons also significantly affected the gum yield; the most gum was obtained in April-June.

THERMAL-CONDUCTIVITY MEASUREMENTS FOR FILLING MATERIALS FOR SLIDING GATES AND THEIR EFFECTS ON FREE- TAPPING PERFORMANCE OF STEEL LADLE

The thermal conductivities of different typical species filling materials for sliding gate systems for steel ladles were measured using a hot wire technique, and the relationships between thermal conductivity and temperature were regressed. The factors affecting thermal conductivity were analyzed by using variance analysis for a perpendicular experiment. The effects of thermal conductivity on sliding gate free tapping were studied, and it was revealed that decreasing the thermal conductivity of the filling materials is beneficial in enhancing the rate of free tapping for sliding gates.

Design Research on Drive System of Underwater Tapping Machine

The underwater tapping machine is composed of a center bit, a tapping cutter, a seal box, a main drive box, a boring bar assembly, a envelop, a gear case, a counter and so on. The drive system in underwater tapping machine consists of a worm drive, a gear drive system and a screw drive. The worm drive is in the main drive box. The worm is connected with a hydraulic motor and driven by the hydraulic motor. The gear drive system is a combined gear train which is the combinations of the fixed axes and differential gear train in the gear case. On the one hand, by means of the fixed axes gear trains the turn and power of transmission shaft are transferred to the boring bar and the screw rod, causing differential turn between the boring bar and the screw rod. On the other hand, the turns of the boring bar and the screw rod are transferred to the differential gear train. The differential gear train is used to drive a special counter to count axial travel of the boring bar. The screw drive is composed of a feed screw and a nut on the boring bar. There is the differential turn between the boring bar and the feed screw. By means of the nut, the boring bar can feed automatically. With the movement of the sliding gear 7 in the gear case, the designed drive system can also be provided with the ability of fast forward and fast backward movement of the boring bar in its idle motion, resulting in the increase of the tapping efficiency.

Theory of higher harmonics imaging in tapping-mode atomic force microscopy

The periodic impact force induced by tip-sample contact in a tapping mode atomic force microscope （AFM） gives rise to the non-harmonic response of a micro-cantilever. These non-harmonic signals contain the full characteristics of tip-sample interaction. A complete theoretical model describing the dynamical behaviour of tip-sample system was developed in this paper. An analytic formula was introduced to describe the relationship between time-varying tip-sample impact force and tip motion. The theoretical analysis and numerical results both show that the timevarying tip-sample impact force can be reconstructed by recording tip motion. This allows for the reconstruction of the characteristics of the tip-sample force, like contact time and maximum contact force. It can also explain the ability of AFM higher harmonics imaging in mapping stiffness and surface energy variations.

Effect of tapping tools and date of tapping on Acacia polyacantha gum yield in South Kordofan State, Sudan

A study was conducted in South Kordofan, Sudan to determine the effect of tapping, tapping tools and date of tapping on the gum yield of Acacia polyacantha. A two-factor experiment was conducted for two seasons in 2008-2009. One location was used for two seasons and two locations for one season. The first factor （4 levels） was the tools of tapping： Makmak, Farrar, and Sonki, and the control which was not tapped. The second factor （2 levels） was the date of tapping that comprises mid October and mid November. These treatments were arranged in Randomaized Complete Block Design and replicated three times. Gum yield （g/tree and g/ picking） was recorded for five pickings. Economic analysis was done using the partial budget technique. The results showed highly significant （p 〈 0.01） differences on gum yield （g/picking and g/tree）. The results indicated that the process of tapping increases gum production by 88.4% and 79.8% compared with un-tapped trees, respectively. The date of tapping has no significant effect on gum yield （g/tree and g/picking） of A. polyacantha. Tapping of the tree with Makmak in mid- November was found to be economically beneficial compared to using the other tools and the control. These results could identify a new source of income for the poor farmers in South Kordofan mainly because of the wild occurrence of Kakamut as a potential gum producing tree species grown naturally in the area.

Effect of grass density and date of tapping on Acacia senegal gum yield in north kordofan state, Sudan

We conducted a two-factor experiment in randomized complete block design with four replications during 2004 in El Demokeya Forest Reserve and El Himaira Natural Forest, North Kordofan State, Sudan. The objective was to develop an understanding of the ecological effects of under-story vegetation and tapping date on the productivity of gum arabic from Acacia senegal as over story cover. The first factor was grass cover which was tested in four levels （100% and 50% grass cover in addition to bare and burnt）. The second factor, date of tapping was tested in three levels namely （1st Oct, 15th Oct and 1st Nov）. The first picking was done after 45 days from tapping and the gum yield up to seven pickings was collected at intervals of 15 days. Gum yield from each picking was collected and weighed using sensitive balance. Analysis of variance was carried out using MSTAT-C statistical package, and the Tukey test was applied for mean comparisons. The results showed highly significant differences （p 〈 0.01） of grass cover on gum arabic yield in the two sites for most of the first consecutive pickings （1st–4th out of seven） in addition to total yield （kg/ha）. With exception to the 4th pickings, the interaction effect between the grass densities and tapping date was not significantly different. The total gum yield was significantly （p 〈 0.05） increased in only two pickings （third and fourth） in El Demokeya Forest Reserve and two pickings （1st and 2nd） at El Himaira Natural Forest. The density of grass cover significantly （p 〈 0.05） affected the number of pickings at both sites; the number of gum pickings was directly proportional to grass density. The number of gum pickings was found to be significantly （p 〈 0.05） increased at the early date of tapping.

Studies on Rubber (<i>Hevea brasiliensis</i>) Trees Exist Plant Type after Planting and Available Tapping Tree of Rubber Plantation in China

Existing plant types of rubber tree after planting and available tapping tree were investigated, and there were about 28 rubber plantations with different tapping years of 8 varieties “CATAS7-33-97”, “CATAS8-79”, “CATAS7-20-59”, “PR107”, “RRIM600”, “GT1”, “INA873”, “93-114”in South China. The results showed that there were six kinds of existing plant types of rubber tree after planting of rubber plantations, which were available tapping trees, wind damaged trees, cold damaged trees, tapping panel dryness trees, absent trees and weak trees, respectively. These data investigated also showed rubber trees under available tapping, stoppage due to tapping panel dryness, absence, wind damage, cold damage and weakness were counted and calculated and made up for 72.21%, 14.75%, 5.61%, 3.86%, 2.68% and 1.89%. Tapping panel dryness trees, wind damage and absent trees are major factors for the loss of tapping rubber trees in the rubber plantations. Of these investigated varieties, available tapping trees per 100 trees of rubber plantation of “PR107”at the 1st, 12th, 14th, 16th, 20th, 24th tapping year were 96, 67, 70, 75, 66, 46 trees in Hainan planting zone, respectively. Available tapping trees per 100 trees of rubber plantation of “RRIM600”at the 9th, 15th, 20th, 22nd tapping year were 88, 62, 55, 36 trees in Yunnan planting zone, respectively. Available tapping trees per 100 trees of rubber plantation of “93-114” at the 10th, 19th, tapping year were 94, 62 trees in Guangdong planting zone. These results showed that available tapping trees of rubber plantation decreased with increasing tapping age under different planting zones in China.

Brief of the technology using sliding gate for slag stopping during converter tapping in the steelmaking plant of Baoshan Iron & Steel Co.,Ltd.

The sliding gate used to stop slag during converter tapping is similar to the control of slide gate in ladle,with the sliding gate device installed outside the BOF tapping hole tip.Owing to the quick opening and closing(in 0.5 s) of the sliding gate,it can not only effectively stop the pre - slag and post - slag during converter tapping but also automatically judge and stop slag with the help of AMEPA slag detecting and PLC control technology.Currently it is regarded as the best process to stop slag during converter tapping.

Enhanced clean steel tapping on BOF vessels with the interstop converter gate type CG series

Trends in today' s steel production show increasing demands for highly-sophisticated steel grades. Therefore,the steel industry will eventually be required to install best performing technologies to meet governmental specifications designed to significantly reduce environmental emissions.Such efforts are supported by innovative new solutions in the entire steel making process.One process that will need to be addressed is the cleanliness of the steel in the liquid steel phase,especially during the BOF-tapping process. The new converter gate(CG)(Fig.1) best supports the slide gate tapping technology for converters in terms of clean steel,productivity,yield and availability-at reduced costs. The CG gate introduces a unique feature for converter slide gates:The bottom plate can be exchanged while the gate remains mounted on the converter.This new feature allows for an increased utilisation of the refractory parts and a significant reduction of the downtime of the converter.This 'designed efficiency' is achieved with a refractory set consisting of three identical plates-two bottom plates and one slider plate-and a nozzle.A number of other improvements such as automatic cylinder coupling using the Interstop SNAP technology and a two step tensioning system have also been implemented. The new system is designed to meet minimal space requirements and therefore will adapt to most BOF shops.To perform preparation,service and maintenance work the modular CG gate can be dismounted from the converter and simultaneously replaced by a ready-to-use unit.The degree of automation for dismounting and mounting as well as for off-line preparation has been enhanced and reduces manual efforts. This paper provides a solution to the obvious trend towards efficient and controlled production of clean steel,in general,and especially at BOF shops.Moreover,it specifically describes the operational results of this innovative BOF tapping equipment at Salzgitter Flachstahl GmbH,Germany.

Molecular Cloning and Sequence Analysis of a Tonoplast Aquaporin Gene TIP1 Associated with Tapping Panel Dryness in Hevea brasiliensis

[Objective]To address the role of aquaporins（AQPs）in the occurrence of Tapping Panel Dryness（TPD）,a phenomenon with tapping incision blocked partly or entirely during latex exploiting in the rubber tree（Hevea brasiliensis）that causes great losses on rubber production,a tonoplast aquaporin gene associated with TPD occurence was cloned and analyzed.[Method]Based on an EST down-regulated in TPD-affected rubber trees,a 774 bp cDNA designated HbTIP1 was isolated from the bark tissue of Hevea brasiliensis with a combination of in silico cloning and RT-PCR.And the gene structure and sequence characteristics were analyzed using bioinformatics tools.[Result]The cDNA includes a 759 bp ORF,8 bp 5’UTR and 7 bp 3’UTR.Sequence analysis indicated that HbTIP1putatively encodes 252 amino acids with a theoretical molecular weight（Mw）of 25.88 kDa and isolectric point（pI）of 4.96.Bioinformatics analysis suggested that the deduced protein is predicted to have six transmembrane helices located to the vacuolar membrane and to harbor one conserved MIP domain that can be grouped into the tonoplast intrinsic proteins（TIPs）of aquaporin family.Homology search revealed that the protein shares a similarity of more than 90%with the homologues in Theobroma cacao,Prunus persica,Citrus sinensis and Ricinus communis,supporting a highly conserved evolution.[Conclusion]This study provided basis for further revealing the regulatory role of AQPs in the TPD occurrence.

Molecular Cloning and Sequence Analysis of an Aquaporin Gene Related to Tapping Panel Dryness in Rubber Tree( Hevea brasiliensis Muell. Arg. )

As a syndrome with tapping incision blocked partly or entirely during latex exploiting in rubber tree （Hevea brasiliensis ）, ＂Tapping panel dryness （TPD）＂ causes great yield losses, thereby becoming the most important factor limiting rubber production. On the basis of an EST down-regulated in TPD-affected rubber trees, a 903 bp cDNA denoted HbPIP2;2 was isolated from the bark tissue with a combination of in silico cloning and RT-PCR. The cDNA contains an 867 hp ORF, 13 bp 5＇UTR and 23 bp 3＇ UTR. Sequence analysis indicated that HbPIP2;2 encodes 288 amino acids with a theoretical molecular weight （Mw） of 30. 71 kDa and isolectric point （Pi） of 8.20. Bioinformatics analysis suggested that the deduced protein is predicted to have six transmembrane helices located to the plasma membrane and harbor one conserved MIP domain that can be grouped into plasma membrane intrinsic proteins （PIPs） of aquaporin （AQP） family. Homolo- gy search revealed that the protein shares a similarity of more than 90% with the homologues in Ricinus communis, Popttlus trichocarpa, Juglans regia and Theobro- ma cacao, suooorting a hie.hly conserved evolution. This study provided basis for further uncovering the regulatory role of AOPs in TPD occurrence.

Real Time Recrystallization Study of 1, 2 Dodecanediol on Highly Oriented Pyrolytic Graphite (HOPG) by Tapping Mode Atomic Force Microscopy

Real-time atomic force microscopy (AFM) imaging revealed for the first time, the detailed growth/dissolution mechanism of Lauryl glycol (LG) or 1, 2 dodecanediol molecules on HOPG at the nano-level after recrystallizing them from chloroform solution. At the early stage of recrystallization, parallelogram-like-structures having lengths of several microns and distinct widths (between ~ 100 - 400 nm) were observed. Growth/dissolution behavior of these parallelogram-like-structures as a function of time was investigated. While dissolution occurred along all three dimensions, growth was found to be strictly two dimensional. Both the growth and dissolution process were found to be logarithmic in nature. The average growth rates along their length and width were found to be 11 nm/min and 1.5 nm/min respectively. Average dissolution rate in percentage on HOPG surface was found to be ~ 0.078%/min. Based upon the recrystallization of LG molecules schematics are drawn for a better understanding of the recrystallization process.

Identifying Sustainable Practices for Tapping and Sap Collection from Birch Trees: Optimum Timing of Tapping Initiation and the Volume of Nonconductive Wood Associated with Taphole Wounds

Experiments were conducted to determine two pieces of information essential to identify practices necessary to ensure tapping trees for birch sap collection is both sustainable and profitable—the selection of the time to initiate tapping birch trees to obtain maximum yields, and the volume of nonconductive wood (NCW) associated with taphole wounds in birch trees. The yields obtained from various timing treatments varied between sapflow seasons, but indicate that using test tapholes to choose the appropriate time to initiate tapping is likely to result in optimum yields from birch trees. The volume of NCW associated with taphole wounds in birch trees was highly variable and generally quite large, averaging 220 times the volume of the taphole drilled, and requiring relatively high radial growth rates to maintain NCW at sustainable levels over the long-term. However, more conservative tapping practices, including reduced taphole depth and increased dropline length, as well as thinning and other stand management practices, can be used to reduce the minimum growth rates required. Producers can use this information to ensure that they use tapping practices that will result in sustainable outcomes and obtain the maximum possible sap yields from their trees.

Power Tapping Function in Near Infra-Red Region Based on 45°Tilted Fiber Gratings

We report an efficient power tapping device working in near infra-red (800 nm) wavelength region based on UV-in- scribed 45° tilted fiber grating (45°-TFG) structure. Five 45°-TFGs were UV-inscribed in hydrogenated PS750 fiber using a custom-designed phase mask with different grating lengths of 3 mm, 5 mm, 9 mm, 12 mm and 15 mm, showing polarization dependent losses (PDLs) of 1 dB, 3 dB, 7 dB, 10 dB and 13 dB, respectively. The power side-tapping efficiency is clearly depending on the grating strength. It has been identified that the power tapping efficiency increases with the grating strength and deceases along the grating length. The side-tapped power profile has also been examined in azimuthal direction, showing a near-Gaussian distribution. These experimental results clearly demonstrated that 45°- TFGs may be used as in-fiber power tapping devices for applications requiring in-line signal monitoring.