Modern forestry vehicles and their impact on soil physical properties

Mechanized harvesting procedures for typical forest vehicles were analysed to examine soil stresses and displacements occurring in soil profiles and to reveal changes in physical properties of forest soils. All field experiments were carried out under traffic lanes of standard forest vehicles in forest stands of the southern Black Forest. The soil stresses were determined using stress state transducers (SST) and displacement transducer systems (DTS) at depths of 20 and 40 cm. Complete harvesting and trunk-logging processes with a total time span of 9 min were observed. The maximum vertical stresses for all experiments exceeded 200 kPa; some experiments showed maximum vertical stresses up to 500 kPa or more at a depth of 20 cm. To evaluate the impact of soil stresses on soil structure, the internal soil strength was determined by predicting the precompression stress. Comparison of soil stress data with the natural bearing capacity of the natural forest soil proves that sustainable traffic is not possible, irrespective of the vehicle type and the working process. Topsoil and subsoil compaction, an increase in the precompression stresses, deep rutting and vertical as well as horizontal soil displacement associated with shearing effects took place and affected the mechanical strength and the physical properties of forest soils. Considering these results, heavy forest machinery has a severe impact on soil physical properties such as air, heat, water fluxes and rootability. In order to sustain the present undamaged soil condition, a change in harvest logistics and organisation is necessary. This can be achieved with a permanent skid-trail system which has already been designed to implement new guidelines in Baden-Württemberg, Germany (Ministerium für Ernährung und ländlichen Raum, Baden-Württemberg 2003, p 27).     

Micro Displacement Measurement System

In order to solve the shortcoming of generally used measure method for Micro displacement,which is expensive and unable to automotive longtime watch,a sort of MDMS is gwen based on the corner reflector and microwave phase measurement.In the situation in which the direction of the micro displacement parallels to that of electromagnetic wave radiation,the basic MDMS is recommended.Otherwise the bend MDMS is recommended.The principle of MDMS is described.The example of channel calculation and circuit for transmitting measure result are also provided.The communication circuit transmits measurement to termination demanded.Finally the experiment results are given.     

Elastic-plastic Displacment Spectrume Based on the Elastic Acceleration Spectrume

This paper calculated the maximum elastic displacment respose based on the elastic acceleration spectrum in the current Seismic Design Code, and find the vary relations of the ratio of the elastic-plastic displacement to elastic displacement with the nature peorid of the SDOM systmes. The simplified formulas to calculate the elastic-plastic displacement are given based on the elastic acceleration specturem in the current Seismic Design Code by regression method.     

奶牛皱胃左方变位临床诊断与整复方法的研究

介绍了奶牛皱胃左方变位的示病性特征,即在左侧腹壁第8～12肋间的肩关节水平线上下听叩诊结合时可听到钢管音,此处的穿刺液pH值<5作为临床诊断的依据;整复方法是以左侧腹壁距腰椎横突下方约25～30 cm,距最后肋骨弓5～8 cm处作为手术切口顶点,垂直于腹中线向下作一长度为15 cm手术切口作为手术部位,然后对皱胃进行复位并对大网膜进行右侧腹壁固定。     

肠式沙障固沙作用及其结构稳定性研究

通过对肠式沙障沙埋程度、积沙宽度、位移程度及沙障控制区域植被盖度等指标进行调查,分别研究了不同规格、不同类型的肠式沙障稳定性及其所在沙丘植被恢复程度。研究结果表明:品字沙障位移距离最大,移动平均距离达到了58.72 cm,方格沙障移动距离最小,仅为36.11 cm。4 m品字形沙障的移动距离最大,达到了70.67 cm,2 m带状沙障的次之,移动距离为52.33 cm,说明规格越大,移动程度也越大。方格沙障铺设沙丘的植被盖度较大,其中4 m×4 m方格沙障铺设沙丘植被盖度达到最大。     

Haemoabdomen and colitis following a colon displacement in a 9‐year‐old Thoroughbred mare

This report describes acute haemoabdomen following phenylephrine administration in a case treated for left dorsal displacement of the large colon. The horse also subsequently developed a severe colitis which was treated with aggressive medical therapy.     

Dual Chamber Pacemaker Implantation in Dogs with Atrioventricular Block

Background: Pacemaker implantation is the treatment of choice for symptomatic bradyarrhythmias. In dogs, a single chamber system is commonly used. In human patients with high-grade 2nd- or 3rd-degree atrioventricular (AV) block, physiologic pacing is recommended, because it improves cardiac output, blood pressure, exercise tolerance, and quality of life. In dogs, this type of pacing is seldom used.
Hypothesis: The implantation of a dual chamber pacemaker in dogs with AV block is a feasible procedure for restoring AV synchrony.
Animals: Thirty-three privately owned dogs with high-grade 2nd- or 3rd-degree AV block were included.
Methods: Patient data of all dogs with AV block presented for pacemaker implantation between December 1997 and November 2004 were reviewed.
Results: Dual chamber pacemaker implantation with AV synchronous stimulation was successfully performed in 33/33 dogs (100%). In 9/33 (27%) major and in 12/33 (36%) minor complications were observed. Mean survival time for the patients discharged from hospital (n = 32) was 33.6 ± 20.4 months (range, 3.9–83.5 months).
Conclusion and Clinical Importance: Dual chamber pacing is a feasible procedure in dogs with 2nd- or 3rd-degree AV block and is not associated with a higher complication rate compared with single chamber pacemaker systems. A major advantage over ventricular demand pacemaker systems is the restoration of AV synchrony for a substantial period of time.     

Relationship between curvature ductility of column and structural displacement ductility for concrete frame structures

Based on the domestic experimental data of multi-storey concrete frame structures, the relationship between curvature ductility of concrete frame column and structural displacement ductility is proposed. 32 sets experimental data of system displacement ductility and the corresponding storey displacement ductility, which are mainly obtained from beam hinge yield mechanism and failure mechanism, are collected, and statistical property of system placement ductility is analyzed. Curvature ductility of concrete frame column is derived from storey displacement ductility factor by the classical analytic solution, and relationship between curvature ductility of frame column and structural displacement ductility is established. Correlation coefficient (R) for fitting power exponent function model and sample test data is 0.775. Results of nonlinear numerical analysis examples show that statistical function model is able to direct the ductility control design of concrete frame column.     

Sternothyroideus myotomy, staphylectomy, and oral caudal soft palate photothermoplasty for treatment of dorsal displacement of the soft palate in 102 thoroughbred racehorses

Objective— To compare racing performance before and after sternothyroideus myotomy, staphylectomy, and oral caudal soft palate photothermoplasty in Thoroughbred racehorses with intermittent dorsal displacement of the soft palate (DDSP).
Study Design— Retrospective study.
Animals— Thoroughbred racehorses (n=102) with DDSP.
Methods— Retrieved data included signalment, primary complaint, and upper respiratory tract endoscopic finding. Lifetime race records were compared for earnings per start before and after surgery, days to 1st start, and races won postoperatively.
Results— Comparing mean earnings per start for 3 races before ($2792) and after ($3806) surgery, racing performance improved significantly after surgery in 63% (46/73) of horses that competed in at least 1 race before and after surgery ( P =.02). Mean and median days to 1st start after surgery were 109 and 69 days, respectively. Of horses that raced postoperatively 65% (60/92) won at least 1 race, and 77% (71/92) raced in >5 races after surgery.
Conclusions— Sternothyroideus myotomy, staphylectomy, and oral caudal soft palate photothermoplasty significantly improved racing performance in experienced Thoroughbred racehorses with performance limiting DDSP, and overall had a similar outcome to other reported surgical techniques for treatment of DDSP.
Clinical Relevance— Sternothyroideus myotomy, staphylectomy, and oral caudal soft palate photothermoplasty should be considered as a surgical approach to correction of DDSP in Thoroughbred racehorses; however, it is possible that staphylectomy may not be necessary to achieve a desirable outcome.     

Development of a hamster model of Chlamydophila pneumoniae infection

The purpose of the study was to evaluate haemostatic function in cattle with abomasal displacement (AD) and to reflect the occurrence of disseminated intravascular coagulation (DIC). Ten adult cattle with left displacement of abomasum (LDA) (group I), 10 adult cattle with right displacement of abomasum with volvulus (RDA) (group II) and 10 clinically healthy adult cattle (control group) were used as material. Numbers of platelets (PLT) and coagulation tests (activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), serum fibrin/fibrinogen degradation products (FDPs), fibrinogen) were measured before the surgical treatment of cattle with LDA and RDA. APTT was prolonged only in group II compared with the control and group I (p<0.05). However, when the individual values of coagulation profiles of each cow were evaluated, two cattle in group I and three cattle in group II had at least three abnormal coagulation profiles, which reflect the occurrence of DIC. These cattle died after surgical treatment. The two cattle with LDA had abnormal APTT, FDPs and PLT values; three cattle with RDA had abnormal APTT, PT, TT, FDPs and PLT values. APTT (5 cases), FDPs (5 cases) and thrombocytopenia (5 cases) were the three most common abnormal tests on coagulation profile in the cattle with LDA and RDA. The results of the study indicate that cattle with AD had a spectrum of haemostatic dysfunction and that DIC was a significant risk factor for mortality.