**4. Conclusions**

In present study the T92/T92 weldments in two di fferent initial PWHT states (i.e., in either conventionally tempered PWHT-1 state or in renormalized-and-tempered PWHT-2 state) were investigated in terms of the electrolytic hydrogenation e ffect on their room-temperature tensile properties and fracture behavior. Here are the main conclusions:

studied weldments in their both PWHT conditions led to additional detrimental effects of their plastic properties. Although the results indicated recognizably higher hydrogen embrittlement susceptibility for the renormalized-and-tempered weldments compared to the conventionally tempered ones, it can be concluded that all studied weldments show sufficient resistance against hydrogen embrittlement in conditions of the present investigation.

**Author Contributions:** Conceptualization, L.C. and L.F.; methodology, L. ˇ C., M.D., V.H. and R.D.; formal analysis, ˇ L.C., L.F., and I.D.; investigation, L. ˇ C., L.F., M.D.; data curation, L. ˇ C. and V.H.; writing—original draft preparation, ˇ L.F.; writing—review and editing, L.F. and I.D.; visualization, L.C.; supervision, L.F. and I.D.; project administration, ˇ L.F.; funding acquisition, L.F. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by "Vedecká Grantová Agentúra MŠVVaŠ SR a SAV" (Grant No.: VEGA 2/0062/19).

**Conflicts of Interest:** The authors declare no conflict of interest.


**6. Conclusion**

cases: a capacitor with and without the proposed material as the insulator of capacitor. The change in dropped voltage depends on the change in capacitance. Accordingly, the change in

foodstuffs are nonmagnetic products [10], the permittivity for each material depends on its moisture content, operating frequency, temperature, etc. [12]. Different models have been proposed to follow the frequency variation of a dielectric such as Drude, Debye, Lorentz and

For food products, the chemical compositions such as salt play a decisive role in dielectric properties of products [10]. Also, dielectric properties can be affected from physical properties, such as bulk density, particle size, and homogeneity [10]. For hygroscopic material, the

The dielectric constant for water is 78 at room temperature. For the moist food, this parameter ranges between 50 and 70, and their loss factor is less than 25 [10]. For organic constituents in food material, the dielectric constant and loss factor are less than 3 and less than 0.1, respec-

Researches and studies have shown that water is the most important part which absorbs microwave energy in foodstuff [10, 17–19]. The dielectric property of water is listed in **Table 1**

**Table 2** lists the dielectric properties of some fruit and vegetable in two frequencies.

**Frequency (MHz) 0.6 1.7 3 4.6 7.7 9.1 12.5 17.4 26.8 36.4** *ε' T* = 20°C 80.3 79.2 77.4 74 67.4 63 53.6 42 26.5 17.6 *T* = 50 °C 69.9 69.7 68.4 68.5 67.2 65.5 61.5 56.3 44.2 34.3 *ε" T* = 20°C 2.75 7.9 13 18.8 28.2 31.5 35.5 37.1 33.9 28.8 *T* = 50 °C 12.5 3.6 5.8 9.4 14.5 16.5 21.4 27.2 32 32.6

is assumed to be the unity, since most of the

capacitance of capacitor is related to the permittivity of material.

**Figure 13.** Open-ended transmission line and its equivalent circuit (reproduced from [12]).

156 Emerging Microwave Technologies in Industrial, Agricultural, Medical and Food Processing

water content is the most important factor in the dielectric constant [10].

While for most of agricultural products, *μr*

Cole-Cole models [10].

tively [10, 17].

for different frequencies.

**Table 1.** The dielectric property of water [10, 20].

The freeze-drying method is described in this chapter. Different relations, related to heat and mass transfer in the system, are mentioned. Time variation of temperature in different layers of system is shown. Then, the interaction between electromagnetic field and molecules of material is expressed. Dielectric properties of different foodstuffs are presented from different references. Different parts of a microwave system are fairly explained, too.

The final stage of freeze-drying method is time-consuming when the frozen region is disappearing. This method is costly and affordable for high-value food like coffee.


**Endemic Infection of** *Batrachochytrium dendrobatidis* **in Costa Rica: Implications for Amphibian Conservation at Regional and Species Level**

**Héctor Zumbado-Ulate 1,\*, Kiersten N. Nelson 1, Adrián García-Rodríguez 2,3, Gerardo Chaves 2, Erick Arias 2,3, Federico Bolaños 2, Steven M. Whitfield 4 and Catherine L. Searle 1**

Received: 28 June 2019; Accepted: 7 August 2019; Published: 9 August 2019

**Abstract:** *Batrachochytrium dendrobatidis* (*Bd*) has been associated with the severe declines and extinctions of amphibians in Costa Rica that primarily occurred during the 1980s and 1990s. However, the current impact of *Bd* infection on amphibian species in Costa Rica is unknown. We aimed to update the list of amphibian species in Costa Rica and evaluate the prevalence and infection intensity of *Bd* infection across the country to aid in the development of effective conservation strategies for amphibians. We reviewed taxonomic lists and included new species descriptions and records for a total of 215 amphibian species in Costa Rica. We also sampled for *Bd* at nine localities from 2015–2018 and combined these data with additional *Bd* occurrence data from multiple studies conducted in amphibian communities across Costa Rica from 2005–2018. With this combined dataset, we found that *Bd* was common (overall infection rate of 23%) across regions and elevations, but infection intensity was below theoretical thresholds associated with mortality. *Bd* was also more prevalent in Caribbean lowlands and in terrestrial amphibians with an aquatic larval stage; meanwhile, infection load was the highest in direct-developing species (forest and stream-dwellers). Our findings can be used to prioritize regions and taxonomic groups for conservation strategies.

**Keywords:** amphibian; chytridiomycosis; conservation; disease; enzootics; epizootics; population declines


**1. Introduction**

Gastrectomy for weight loss was first described by Marceau et al. in 1993 as a restrictive component of biliopancreatic diversion [1]. Then they described the vertical sleeve gastrectomy as the first step of the biliopancreatic diversion-duodenal switch procedure in 1998 [2].

Unfortunately, the laparoscopic duodenal switch was associated with significant complications, especially in patients with high body mass index [3]. Thus, Gagner et al. performed laparoscopic sleeve gastrectomy (LSG) as the initial stage of a twostaged approach before BPD/DS and Roux-en-Y gastric bypass to optimize the performance status of patients at high surgical risk or extremely obese [4, 5]. Many of these patients achieved adequate weight loss and improvement in medical comorbidities

after the first sleeve gastrectomy, and the second stage was rarely required. Therefore, LSG has evolved into a stand-alone weight loss procedure over time.

Long-term data show that LSG is as similar in weight loss and comorbidity resolution as the Roux-en-Y gastric bypass and has similar mortality and morbidity rates [6]. It is now the most commonly performed bariatric procedure worldwide, owing to its technical simplicity, short learning curve, and effectiveness [7].

The procedure has not been standardized yet. Different technical nuances can be seen at various points throughout the process. In this section, we focus on our method in detail, including all operative steps, which we believe is the simplest and most effective technique after performing over 5000 surgeries at our institution.